In the first of two instances in the film [the second time is at the police station when Dix meets Kesler], Dix theorizes his solution to the murder mystery. Dix suggests how it was committed by having Brub and Sylvia re-enact the crime. As a director of the re-staging, he positions the two as actors within a set, explains their motivations, and has them convincingly believe what he has represented to them. To begin, Dix tells them that they need to have "enough imagination to visualize the crime." He puts two chairs together - the driver and passenger front seats of the car. Brub is designated as "the killer" who drives the car, while Sylvia is the victim-passenger. Dix explains why the murder was committed in the car - if she had been killed earlier, her body would have been put in the back seat or trunk, and he would have had to stop to dump the corpse.

As he describes the chilling moments leading up to the strangulation, Dix's eyes are menacingly highlighted (as they were during the opening credits). He instructs Brub to strangle his spouse during the frightening scene, and Brub almost unwittingly chokes Sylvia:

You put your right arm around her neck. You get to a lonely place in the road and you begin to squeeze. You're an ex-GI. You know judo. You know how to kill a person without using your hands. You're driving the car and you're strangling her. You don't see her bulging eyes or her protruding tongue. Go ahead, go ahead Brub, squeeze harder. You love her, and she's deceived you. You hate her patronizing attitude. She looks down on you. She's impressed with celebrities. She wants to get rid of you. Squeeze harder. Harder. Squeeze harder. It's wonderful to feel her throat crush under your arm.

Dix sits back after his effective demonstration: "Now, are you convinced?" Sylvia is unsure and proposes what was missing from the dramatization: "You forgot my hands. I could scratch his eyes out before he could kill me." Dix disagrees: "Ah, but you didn't. Your first instinct was to grab his arm, try to loosen his grip. That's where you lost the battle, just as Mildred did." He then boasts about externalizing his emotions through his scripts:

I've had a lot of experience in matters of this kind. I've killed dozens of people, in pictures.

Then he reassures the fearful Sylvia:

No, Sylvia, I didn't do it. I assure you, I could never throw a lovely body from a moving car. My artistic temperament wouldn't permit it...You see, we so-called creative artists have a great respect for cadavers. We treat them with the utmost reverence. Put them in soft beds, lay them out on fur rugs, leave them lying at the foot of a long staircase, but we definitely could never throw them from a moving car as though they were cigarette butts.

As Dix leaves the dinner engagement, he reminds Brub to give Lochner "a detailed report" about his theory of the murder: "Tell him to look for a man like me, only without my artistic temperament - which may or may not be phony." With Dix gone, Sylvia confides in Brub that she is unsure of Dix's sanity and strange behavior:

He's a sick man...There's something wrong with him....He's exciting because he isn't quite normal.

During their brief argument, Brub compliments his superior-thinking friend for being "an exciting guy" - "There's nothing the matter with his mind except that he's superior...Maybe us cops could use some of that brand of abnormality. I learned more about this case in five minutes from him than I did from all our photographs, tire-prints, and investigations."

When Dix returns to his apartment, he contemplates the idea of paying a late night call to Laurel. Once inside her apartment, he cowers by the front door, but then is accusatory: "You annoy me." He admits that he only had one drink at dinner: "I knew I was going to see you." Finally, after she permits him to sit down and relax, he softens and approaches her - and from then on invades the privacy of her apartment quite often. When asked who she was speaking with on the phone -- she responds that it was her 50-ish married masseuse Martha with a son at UCLA -- "the only thing left of my movie career...She comes to me twice a week, beats me black and blue."

He interrupts and asks about her possible interest in him: "Have you thought about it a second time?" She nods: "I'm interested" - a decision to become involved with him - made the previous afternoon at 3 pm. He bends down and kisses her - he ominously takes her face in his strong hands, and also holds her by the neck. [Note: this is a stance he will later take in a more deadly fashion.] For Dix, he explains how love and redemption are interlinked with violence and death:

I've been looking for someone for a long time. I didn't know her name or where she lived. I'd never seen her before. When a girl was killed - and because of that, I found what I was looking for. Now I know your name, where you live, and how you look.

[Note: His statement that he knows her name, where she lives, and how she looks could be the contented thoughts of a disturbed stalker.]

Sometime within the next few weeks, a snooping Mel checking in on Dix is amazed and delighted to find him writing the screenplay in his apartment, with Laurel having temporarily moved in with him. She is carrying a tray of water, and in his bedroom making up the sheets and fluffing the pillows. According to Laurel who has become Dix's script typist, the exhausted "genius" Dix is working non-stop: "He hasn't stopped working all night. He hasn't left the house in days." She jokes with Dix for being so obsessed with his work: "You're a horrible, conceited good-for-nothing, and I don't love you." When she urges him to get some sleep, they tease each other - as lovers:

Dix: If you don't let me alone, I'm gonna kick you right outta here.
Laurel: If you do, I'll go back to Chicago and be a Fuller Brush girl. They were crazy about my work in the Near North Side.
Dix: You go when I tell you to go, and not before. Remember that.
Laurel: I'll try.

As Dix sleeps, Laurel is again summoned by Sgt. Nicolai to return to the police station for more questioning by Captain Lochner, three weeks since the Atkinson murder. He opens the interrogation by stating: "Certain facts seem to contradict your original statement." He wonders why Laurel originally said that she didn't know Dix, but now they are almost "inseparable." She explains how she has become Dix's script typist - an unsalaried position - "I'm doing it for love...I am in love with Mr. Steele." He asks why she is defiant and not very helpful in the case, and has a chip on her shoulder. He begins planting seeds of distrust and doubt in her mind:

Aren't we on the same side in this matter? Doesn't it frighten you that there's a killer at large? He may be in your apartment house or next door. Certainly in your neighborhood.

He shows her pictures of normal-looking men - each one is a "ruthless maniac" who has committed a horrible murder. Mildred's murder is not very understandable: "She had no money, no enemies. It wasn't a sex murder. It was the act of a sick mind with an urge to destroy something young and lovely." Laurel explains her upset at the suspicion surrounding her lover - the Captain's "most logical suspect." He points out Dix's lengthy record of violent behavior: "Fights, scandals, destruction. It all adds up to the same thing: an erratic violent man." Laurel defends Dix: "All this happened years ago. He's changed since." Captain Lochner refers to Dix's re-enactment of the killing at Sgt. Brub's house, declaring: "Obviously, killing has a fascination for him." After Laurel leaves the office, Mildred's boyfriend Henry Kesler (Jack Reynolds) arrives for further questioning as well.

At a nightclub, Dix and Laurel listen to a singer-pianist (black singer Hadda Brooks) perform the slow jazzy song at a piano bar: "I Hadn't Anyone Till You" (written by Ray Noble in 1938):

I hadn't anyone till you, I was a lonely one till you.
I used to lie awake and wonder if there could ever be
Someone in this wide wide world just made for me
Now I see I had to save my love for you
I never gave my love till you
And with my lonely heart demanding it
Cupid took a hand in it, I hadn't anyone till you

After Dix asks: "Anything you want to make you happy?", Laurel whispers a response in his ear: "I wouldn't want anyone but you." Dix is angered by the arrival at the club of Deputy Ted Barton - with his wife - to tail him and invade their privacy and intimacy. Dix and Laurel briskly leave for Paul's Restaurant, as Dix tells Barton on the way out: "I want to do everything I can to make your job easier." Barton tells his wife at the piano bar: "I could see why that guy gets into a lot of trouble."

The next scene in Laurel's bedroom is strangely filmed at a very low camera angle - Laurel lies on a massage table with her face almost next to the camera, with her chin resting on her two hands. Hovering above her and giving her a rough rubdown is a large, grim-faced Martha (Ruth Gillette, uncredited), her long-time masseuse. Laurel is told that her nerves and muscles are "tied up in knots" from typing all day, and having only six hours of sleep: "You can't be a nursemaid and a sweetheart, a cook and a secretary. You've got to think of yourself." Martha tries to dissuade Laurel from her recent loving relationship ("I've never been happier in my life"), and reminds her of the "lovely pool" Mr. Baker had built for her up on Miller Drive. Laurel argues that Baker only wanted to increase the property value and was about to raise the rent. Martha suggests that Laurel shouldn't have left Baker, and should return to him - to ensure her own "security." [Note: Martha possibly represents Laurel's subconscious.]

Dix enters Laurel's outer living room with a stack of presents for her, and then requests a full breakfast - she promises to prepare it for him in 10 minutes. Martha continues to dissuade Laurel from associating with Dix, due to his past history of abusing his former girlfriend:

They still don't know who killed that checkroom girl...Have you met Frances Randolph?...I used to take care of her...Just beat her up. Broke her nose...You can joke about it, angel, but someday you'll find out who your friend is. I only hope it isn't too late, because this isn't going to be as easy to get out of as it was with Mr. Baker...(Laurel orders her out) I'll get out, angel, but you'll beg me to come back when you're in trouble. And you will, angel, because you don't have anybody else.

That evening, Dix and Laurel attend a beach party "picnic" hosted by the Nicolais, since Dix has been working "like a fiend" all week. He claims he has been inspired by Laurel: "I wouldn't write a page if it wasn't for her." He then complains about the women in Hollywood, very unlike new girlfriend Laurel:

That's the trouble with these Hollywood dames. They all have such a sketchy education. They know absolutely nothing about the community chest, but they know everything there is to know about community property. Their arithmetic is not so hot, but just ask them how many minks make a coat.

Sylvia suggests to the loving couple: "Dix needs you, Laurel. You ought to marry him. You have to marry him. You promised Lochner you'd invite him to the wedding." Sylvia inadvertently reveals that Laurel had a second meeting with the Police Captain - something Laurel didn't tell Dix. His temper explodes at Laurel and Brub, sensing their distrust that he is still a suspect under surveillance (and a watchful eye): "Still checking on me. Still trying to pin a murder on me."

He takes Laurel on a scary and reckless, nocturnal, 70 mph ride in his convertible onto winding Mulholland Drive. Significantly, both of them sit side by side facing forward, without looking at each other, distrustful of each other now that she has been deceitful about a second police interrogation. He side-swipes the driver's side of another car after driving through a stop-sign. The other driver, a young UCLA college star named John Mason (Don Hamin, uncredited), yells at Dix for ruining his recent $200 paint-job:

Why, you blind knuckle-headed squirrel!

In a clear case of misdirected road rage, Dix blames the accident on the other driver, and punches him, until the young kid is unconscious by the side of the road. Laurel intervenes ("Dix, stop! You'll kill him!") and prevents him from bashing in the head of the college boy with a large rock. This is the beginning of the end for Laurel's love for Dix - she clearly sees him as a man whose own sur-'face' hides terrible, uncontrollable and ferocious anger. She fears that he is capable of murder. As they drive off, she hides her face from him with her hand. They park on a deserted road, where he suspiciously places his strong arm around her head/neck and asks for a cigarette. He blames the other driver - during their first argument:

Dix: These guys in hopped-up cars, they think they own the road.
Laurel: You weren't really angry with him. You've been wanting to slug somebody ever since you left the beach.
Dix: What happened at the beach had nothing to do with it. This guy asked for it. I've had a 100 fights like this.
Laurel: Are you proud of it?
Dix: No, but I'm usually in the right. I was this time. You heard what he called me.
Laurel: That doesn't justify acting like a madman.
Dix: Nobody can call me the things he did.
Laurel: A blind, knuckle-headed squirrel. That's real bad.

After Laurel takes the wheel and they drive away, Dix recites a line from his forthcoming script (although he worries where to place it: "I don't know quite where") - a foreshadowing of the end of their own fragile affair:

I was born when she kissed me. I died when she left me. I lived a few weeks while she loved me.

Laurel suggests it could be "a farewell note." He has her repeat the line to him.

The next day at the Beverly Hills post office, Dix purchases a postal money order for $300 to be sent to John Mason in Santa Monica, from Mr. Joe Squirrel. He also visits with detective friend Brub at the police station, advising: "If you want to find out anything about me, ask me." Dix is introduced to another suspect, Henry Kesler, and offers his second theoretical solution to the murder mystery:

Trying to pin this thing on you, the same as they are on me?...As a matter of fact, you're a much more logical candidate than I am. You're in love with her. You could have been jealous. If I were Captain Lochner, I could, uh, build up a pretty good case against you.

At the same time, Laurel is with Sylvia, apologizing for Dix's "temperamental" behavior at the beach party the previous night: "There was no excuse for his behavior." Laurel is concerned that Dix, no matter what his profession, would still have inherent rage: "I'm afraid he'd act just the same no matter what kind of work he did." Laurel then asks about the 'imaginative' re-enactment of the crime, showing her initial worry that Dix is a suspect, although Sylvia attempts to assure her: "You know Dix didn't do it. You saw him after the girl left." [Note: Laurel does not confirm, one way or the other here, that she saw Dix after Mildred left.] Laurel also believes that the suspicious Captain Lochner was trying to warn her of Dix's anger, and then confesses she is confused and fearful about him:

There is something strange about Dix, isn't there? I keep worrying about it. I stay awake nights trying to find out what it is. And then he shows up for breakfast with an armload of packages, and he's so sweet and so kind.

She then tells Sylvia what she cannot express to him:

What can I say to him? 'I love you but I'm afraid of you. I want to marry you but first convince me that Lochner's wrong, that you didn't kill Mildred Atkinson.'

Sylvia blurts out that the anxious Laurel should go away for awhile - for her own personal safety - and then softens her advice: "Give yourself a little time. Figure things out quietly." Laurel's suspicions about Dix's explosive anger are confirmed and amplified by Sylvia's reactions.

At night, Laurel tosses and turns, and in her mind (with superimposed flashback images), she again hears the ominous opinions and warnings of both her masseuse and Lochner, confirming that Dix is violent and has a "sick mind with an urge to destroy." The cleaning lady Effie (Ruth Warren, uncredited) vacuuming in Laurel's apartment divulges to Dix that Laurel has begun taking sleeping pills. In an off-handed comment, Effie suggests that the two get married and go on a honeymoon, so she can get their two apartments "cleaned up."

Laurel is passively doped up when she awakens, and joins Dix in the kitchen cutting up grapefruits for their breakfast with a curved knife that he has straightened. She tells him that she likes the love scene in the script that he has written. He discusses what a good romantic script would be in a Hollywood movie - it would be similar to what is realistically being played out between the two of them, without moonlight, misty-eyed lovers, and romantic music. But he doesn't realize that their love is already threatened and breaking apart (they are unbalanced by being positioned far 'apart' from each other in the kitchen, and he uses the 'past' tense to describe their love). He is incapable of living an ordinary existence as a common man who prepares breakfast for his wife:

That's because they're not always telling each other how much in love they are. A good love scene should be about something else besides love. For instance, this one: me fixing grapefruit, you sitting over there, dopey, half-asleep. Anyone looking at us could tell we were in love.

Dix reiterates his love for her and encourages Laurel to get married to him. He believes that they are now in love - replicating the movie script: "I always knew I'd get stuck with you eventually. All I needed was a little push." She is apprehensive that Dix wants to "know everything" about her and has a compulsive need to be in charge of the pace of their relationship. She reiterates her wish to go slowly: "I love you. But there's no reason to rush into anything."

Then, Dix asks Laurel to respond to him in 10 seconds about his sudden marriage proposal -- he will buy an engagement ring, and invite "select friends and enemies" to Paul's for a celebratory party. They could then take a midnight plane to Las Vegas and be married by the next day. Fortunately, a pot of boiling coffee interrupts Laurel's delayed response. He grabs her from behind in the kitchen and insists on a "simple yes or no" answer, without any qualifications. Out of fear, she accepts to avoid aggravating him or getting into an argument.

When he leaves to make arrangements, Mel arrives to congratulate Laurel, who is on the phone attempting to reach Martha - to rescue her from her troubling predicament. Laurel breaks down in tears - admitting that she is leaving town and will not marry Dix. Mel responds: "I was hoping for a miracle, and it didn't happen." Laurel explains her reason for refusing marriage, while Mel rationalizes Dix's inherent, explosive nature:

Laurel: Dix doesn't act like a normal person. You don't go around hitting people, smashing cars, torturing your best friend. I'm scared of him. I don't trust him. I'm not even sure he didn't kill Mildred Atkinson.
Mel: Laurel! You're going too far.
Laurel: Am I? Have you forgot what you asked me when we first met? You weren't sure of him either, and you knew him better than anybody else. Why can't he be like other people? Why?
Mel: (explodes angrily) Like other people? Would you have liked him? You knew he was dynamite! He has to explode sometimes. Years ago, I tried to make him go and see a psychiatrist. I thought he'd kill me. Always violent. Well, it's as much a part of him as the color of his eyes, the shape of his head. He's Dix Steele, and if you want him, you've got to take it all, the bad with the good! I've taken it for 20 years, and I'd do it again.
Laurel: You make me feel ashamed, Mel.

Realizing that Laurel is actually going to turn down Dix's offer, even though she consented to be married, Mel is concerned: "Dix has a tremendous ego. He can't take defeat...If Dix has success, he doesn't need anything else." Laurel is determined to leave before Dix returns, and decides to give Mel the finished script (without Dix's knowledge or consent) to give to producer Brody - so that the blow of her rejection and departure will be minimized. She evaluates its quality: "It's really wonderful." Laurel then makes arrangements to fly to New York at 3 pm, if she can get a reservation, but she is compelled by Dix to join him at the ring shop, look at houses, buy clothes, and participate in a small engagement party at Paul's restaurant that evening.

At their party's dining table at Paul's, Dix learns that his ex-girlfriend Fran Randolph has been asked by Brody to read the script, and possibly play the part of Althea. Dix is upset that his agent Mel, who "should have known better," delivered the finished script to Brody that morning without his knowledge. When Mel tries to shield Laurel by claiming that he stole it out of Laurel's desk, Laurel speaks up and admits her shared guilt. Mel complains that the script isn't a "faithful adaptation" of the trashy book that the "impatient" Brody had asked for. Dix accuses Mel of being a thief, and then asks: "Why is it so important that Brody read the script today?" A phone call from Martha for Laurel is intercepted by Dix, who then slaps Mel in the face, breaks his glasses, and slightly cuts his face. To his surprise, Dix is told by director Lloyd Barnes that Brody is "delighted" and "raving" about the script. After Dix makes up with Mel in the men's room, he finds that Laurel has left the ruined and cancelled dinner party.

Dix pursues Laurel, just missing an important phone call from Sgt. Brub Nicolai taken by proprietor Paul - that Henry Kesler confessed to Mildred's murder, and also unsuccessfully tried to commit suicide by shooting himself in the chest. At his apartment complex, Dix hears his own phone ringing, but ignores the long-awaited announcement of his innocence on his way up to Laurel's apartment. He bangs on her locked door to be let in, as she is hurriedly packing her bag inside her bedroom to leave. When he finally gains entry, she has changed into a bathrobe and locked her bedroom door. In the living room, he first apologizes for interrupting her phone call and for striking Mel in the restaurant.

But then he notices she has removed the engagement ring that he had just bought for her. He demands that her missing ring (in her jewel box) be returned to her finger. He is further angered when he finds her bedroom door locked (she claims it's a mess inside and wants to keep it out of his sight) - a symbolic gesture to keep him away. Laurel flees to her bedroom, where she rips up a farewell note on her nightstand, to keep Dix from seeing it. Suddenly, Dix's eyes widen and he barges in, accusing Laurel of packing - not for a honeymoon trip to Las Vegas - but to run away from him ("like you ran away from Mr. Baker"). She screams: "I can't take any more of this!" And then, when he answers her ringing phone in the living room, he takes a message that her single-ticket flight reservation to New York has been cancelled.

Turning demented, with a furious look in his eyes, he enters her bedroom, grabs her by the face and throat and is about to choke her. She begs: "I'll stay with you, Dix, I promise. I'll stay with you. I love you, Dix. I'll marry you. I'll go away with you. Take me..." He doesn't believe her: "You'd run away from me the first chance you get." She asserts: "Don't act like this, Dix, I can't live with a maniac." He has a stranglehold on her: "I'll never let you go." As she pleads for her life, the phone rings and he is prevented from strangling her to death. [Note: In the original film version, Laurel was murdered, but director Ray demanded a revised, reshot ending.] Dix breaks away and wearily answers. The call is from detective friend Sgt. Brub Nicolai - with news that will take the "tension" off of Dix and Laurel - a confession from Atkinson's fiancee - "an airtight confession from Kesler." Lochner then takes the phone and apologizes to both of them.

Dix hands the phone to Laurel: "A man wants to apologize to you." Laurel hears from Lochner that Dix has been cleared of the murder, and that the authorities are apologetic for putting them through such an emotionally-painful "ordeal." Laurel replies that it's too late to save their relationship - the delay in the phone message getting through has pushed both of them toward withdrawal of love:

Yesterday, this would have meant so much to us. Now it doesn't matter. It doesn't matter at all.

In the bleak ending, Dix exits her apartment, and she watches him teary-eyed (filmed in closeup). Dix is viewed from a high angle as she observes him walk down her stairs and across the patio, past the fountain and toward the outer archway, to leave the complex without looking back. The final ambiguous view shows his solitary desolation and uncertain future. She murmurs as she repeats the bittersweet words from Dix's script (the film's last lines), while leaning wearily on her apartment's door frame:

I lived a few weeks while you loved me. Goodbye, Dix.