To snap him out of his doldrums and as a "nice gesture," his parents, nonetheless, suggest a date with Mrs. Robinson's daughter when she is home from college - she is a former high school classmate of his. Their pressuring and prodding forces him to slip into the pool, and he swims underwater beyond their reach. But the situation does become complicated when he is railroaded into a date with Elaine. As he is escorted into the Robinson household to take Elaine out, an "extremely upset" Mrs. Robinson glares at him. The Newlywed Game is also blaring on the television set, adding a comic undercurrent to the situation. In contrast to her darkly-garbed mother, Elaine is dressed in pink.

Unenthusiastic about the prospect of the date, he deliberately tries to put Elaine off by being offensive. Without communicating with her (wearing his sunglasses at night), he drives recklessly in his sports car and then marches ahead of her into a tawdry strip joint. The stripper twirls the dangling tassels on her bare, rotating breasts directly behind Elaine's head, while Ben asks:

You're missing a great effect here. How'd you like that? Could you do it?

He removes his sunglasses [his barrier] as he sees tears forming in her eyes, and stops the tawdry show. Disgusted and humiliated in shame, she runs out. Benjamin pursues her, apologizes, and calms her down, explaining that the date was their parents' idea: "That's why I've been acting this way. I'm not like this. I hate myself like this. Listen, could you just stop crying, please?" Then he kisses her.

At a drive-in restaurant while they stuff their faces with food in his open-topped convertible, she empathizes when he explains his rudeness, and expresses his genuine feelings for the first time in the film:

I've had this feeling ever since I graduated. This kind of compulsion that I have to be rude all the time...It's like I was playing some kind of game, but the rules don't make any sense to me. They're being made up by all the wrong people. I mean no one makes them up. They seem to make themselves up.

Surrounded by typical 60's teenagers who are listening to loud rock and roll music on a car radio, Benjamin turns and asks that they "turn that down a little." Alienated from his own generation, they ignore him - disrespectful of his request. The music keeps blaring. To isolate themselves from their own crowd and its noise, he pulls up the convertible top on his red Alfa Romeo. They finish their conversation inside the car, but the out-of-synch soundtrack continues playing the loud music [Simon and Garfunkel's Big Green Pleasure Machine] on the exterior.

Before the night is over, they find themselves at the Taft Hotel for a drink - humorously, Ben is recognized by most of the hotel employees and greeted as "Mr. Gladstone." After hurriedly leaving the hotel because he can't explain everyone's familiarity with him, he drives her home. Before dropping her off, he realizes that she is actually the only person he can talk to - he confesses his love for her - a love that is almost impossible given the circumstances:

Benjamin: Elaine, I like you. I like you so much. Do you believe that? (She nods silently) Do you?
Elaine: Yes.
Benjamin: (He sighs deeply) You're the first thing for so long that I like, the first person I could stand to be with. My whole life is such a waste. There's just nothing. I'm sorry. I'll take you home now. (He starts his car)

Point-blank, she senses his inner despair about his life and asks: "Benjamin, are you having an affair with someone?" (He turns his car's engine off.) He relates the story of his unsatisfactory relationship with an older married woman. When she asks: "And it's all over now?" he answers affirmatively. With a blossoming affection for each other, Elaine agrees to see Benjamin the following day for a drive.

The next day in the pouring rain outside the Robinsons' house, a pair of women's legs run up to Benjamin's car at the curb. Notably and surprisingly, they are not Elaine's legs but Mrs. Robinson's - she intercepts him before he can get out of his car, and hops in. Projecting menace and determination, she hysterically threatens an ultimatum - she will unpleasantly divulge "everything" about their affair if he continues to show any interest or have contact with Elaine. Not believing her and thinking that confessing the truth to Elaine first will solve everything, Benjamin makes a major miscalculation. He rushes into the Robinson house and rushes to Elaine's upstairs bedroom - where he finds her startled to see him - and half-dressed. A totally-soaked Mrs. Robinson pursues close behind.

With the bedroom door half shut, in the so-called 'reveal scene,' Benjamin begins to confess to Elaine the identity of the "older woman" of his affair:

That older woman that I told you about?...The married woman. That wasn't just some woman...

At the same moment, Benjamin glances beyond Elaine and sees her mother standing outside the partially-closed door and looking back at him. After Elaine innocently asks: "What are you telling me? Benjamin, will you just tell me what this is all about?", Elaine notices the direction of Ben's eyes and turns to see her mother in the doorway. Turning back to face Benjamin, Elaine's out-of-focus face slowly comes into focus [a superb rack-focus shot] as she realizes the woman having an affair with Benjamin is her mother. Totally offended and hysterical, Elaine first reacts: "Oh, no. Oh, my God!" and then refuses to speak to him. She screams as she orders him out. Mrs. Robinson bids him a mortal-sounding goodbye ("Good-bye, Benjamin") as the camera pulls back from her black-clothed, disheveled image in the corner of the white upstairs hallway. The scene ends on her diminished, small, and pathetic state when the shot dissolves to black.

Another montage of dialogue-free images accompany the Simon and Garfunkel song Scarborough Fair [a song that is associated with an eventually promising relationship with Elaine].

Are you going to Scarborough Fair?
Parsley, sage, rosemary and thyme
Remember me to one who lives there
She once was a true love of mine...

Benjamin blankly stares into his aquarium tank, pushes his cigarette ashes off a ledge, drives aimlessly around town in his sports car, observes her from afar (through sunglasses and his rear view mirror), observes the pool maintenance man clean their pool through the upstairs window, and watches as Elaine's father packs the car for her departure to college at Berkeley in the Bay Area of Northern California. His notepad is covered with his words reflecting his obsession: "Dear Elaine Elaine ---, Elaine ---, Elaine ---, Elaine ---."

Ben unrealistically boasts to his parents about a firm decision he has made: "I'm going to marry Elaine Robinson." They are very pleased until they realize his plan is "half-baked" and improbable. They are even more jolted when he tells them that Elaine doesn't like him. (Toast pops out of the toaster to accentuate the point.) He determinedly pursues her to Berkeley. A camera shot of Benjamin driving across the Oakland Bay Bridge suddenly sweeps into the air. He tracks her around the university campus on her way to classes, and then rents a temporary room. The proprietor (Norman Fell) is suspicious of the new tenant as they climb many flights of stairs, even though Benjamin is totally clean-cut and innocuous:

Proprietor: Are you a student?
Benjamin: Not exactly.
Proprietor: What's that?
Benjamin: I said 'Not exactly.' No.
Proprietor: What are ya then?
Benjamin: Oh, I'm just sorta travelin' through.
Proprietor: I like to know who's living in my house. Like to know what my boys are up to.
Benjamin: I'm not up to much, actually. I'm just visiting. I mean, I've always wanted to see Berkeley.
Proprietor: (He stops at one of the landings) You're not one of those agitators?
Benjamin: What?
Proprietor: One of those outside agitators?
Benjamin: Oh no.
Proprietor: I hate that. I won't stand for it. I won't stand for that.

After persistently observing Elaine for days without approaching her, he eventually reveals his presence to her by chasing after a bus she has boarded [the first of two bus rides with him in the film] to leave campus. On the moving bus, he calls their meeting a wonderful "coincidence." She is uneasy in his presence, informing him that she is on her way to the zoo to meet someone. Although she doesn't order him away, she can't understand what he is doing following her there, especially since she has started dating a preppy, pipe-smoking medical student Carl Smith (Brian Avery).

One day while he is shaving in his rented room [another shaving scene, connected to the earlier one when his mother questioned him about his late-night affairs - with Mrs. Robinson], Elaine bursts into his rented room unexpectedly and demands an explanation for his actions with her mother, believing that he raped her. When Benjamin tells her the real story, she screams to cover over his words. She reluctantly believes his account and realizes that her mother was lying. As he packs to leave the boarding house (ordered out by the landlord), she asks what he is going to do next:

Ben: I don't know.
Elaine: Are you going home?
Ben: No.
Elaine: Well, where are you going?
Ben: Elaine, you're going to have to stop asking me that.
Elaine: I don't want you to leave tomorrow.
Ben: I don't understand.
Elaine: I don't want you to go anywhere until you have a definite plan.

Later, she appears in his darkened room where he is sleeping and wakes him. Drifting back into his dream-like consciousness in a blissful, entrancing scene, she turns his dream into a potential reality - she reveals her feelings for him and mildly encourages him. He exclaims after it's all over: "Good God!"

Elaine: Benjamin...Will you kiss me? (He rises from bed)
Ben: (After a sleepy kiss.) Will you marry me? (She shakes her head no.) You won't?
Elaine: I don't know.
Ben: But you might?
Elaine: I might.
Ben: Is that so? You might marry me?
Elaine: Yes.
Ben: When?
Elaine: I don't know.
Ben: What about tomorrow? I don't mean to be pushy but...
Elaine: I don't know. (They embrace) I don't know what's happening.
Ben: You mean you're confused? (She nods her head yes.) Look. Don't be confused. We're getting married.
Elaine: I don't see how we can.
Ben: We just can.
Elaine: I have to go now.
Ben: Elaine. Are you serious about this?
Elaine: I'll think about it.
Ben: You really will?
Elaine: Yes.
Ben: (After she's left and gone down the stairs) Good God!

Encouraged but shocked that his own obsession might come true, Benjamin doggedly pushes in the direction of marriage daily, although Elaine is unable to definitely commit herself. After asking numerous times about blood tests, Benjamin is told that he should drag her off:

Elaine: I just don't think it would work.
Benjamin: Why wouldn't it? (The school bell rings, signaling the beginning of Elaine's academic class. Benjamin waits outside the door until the bell rings again and they continue where they left off - probably an hour earlier) Why wouldn't it?
Elaine: I just don't think it would.
- in Elaine's physical education class -
Benjamin: Tomorrow? Can we get our blood tests tomorrow morning?
Elaine: Why don't you drag me off if you want to marry me so much? [foreshadowing the film's climax]
Benjamin: Why don't I just drag you off? All right, I will. Right after we get the blood tests...

Although Benjamin is entirely convinced that they will marry, Elaine announces a new hurdle - she has semi-committed herself to Carl Smith, ("that guy at the zoo"), a friend of the Robinson family. While she studies in the library, he persists in asking about his rival and the way she was propositioned: "How did he do it? Did he get down on his knees? He didn't get down on his knees, I hope...Well, what did he say? I'm curious." There are more repetitive questions from Benjamin and ambiguous responses for Elaine:

Benjamin: Are we getting married tomorrow?
Elaine: No.
Benjamin: Day after tomorrow?
Elaine: I don't know. Maybe we are - and maybe we're not. (She leaves the frame. After ten seconds, she returns and kisses him.)

Benjamin purchases a ring, gifts, and a bouquet of white flowers for her. When he returns to his boarding room house, he is met by a despising Mr. Robinson in an angry confrontation. Mr. Robinson feels resentful of Ben's affair, although Benjamin explains that he has no personal grudge nor disrespect. Mr. Robinson is divorcing his wife, thinking it a direct consequence of Benjamin's relationship with his wife. Benjamin doesn't think so:

What happened between Mrs. Robinson and me was nothing. It didn't mean anything. We might just as well have been shaking hands...The point is I don't love your wife, I love your daughter, sir.

In no uncertain terms, Benjamin is ordered to never see Elaine again and to get her off his "filthy mind." Without Benjamin's knowledge, Elaine has left school, but has left a 'Dear John' note for him (read in voice-over by Elaine) to challenge him even further

Dear Benjamin. Please forgive me, because I know what I'm doing is the best thing for you. My father is so upset you've got to understand. I love you but it would never work out.

After being thrown out of his boarding house and compelled to find her to fulfill her testy request: "Why don't you drag me off if you want to marry me so much?", Ben's frantic search for Elaine is set to the sounds of a strumming guitar, Simon and Garfunkel's "Here's to You Mrs. Robinson." He hurriedly drives to Los Angeles from Berkeley [400 miles away], then sneaks into the Robinsons' home where he is promptly reported to the police as an unarmed burglar by Mrs. Robinson. He learns that Elaine's parents have intervened and set her up to marry the bland Carl Smith. He turns right around and drives back to Berkeley [another 400 mile drive] and visits Smith's fraternity. There, he learns the wedding is taking place in Santa Barbara [another 300 mile drive]. After another long drive, he reaches Santa Barbara and cleverly learns the location of the wedding by telephoning the office of the groom's father. But his car runs out of gas a few blocks from the church where the wedding is in progress.

In the memorable climactic rescue scene at the film's conclusion, Benjamin makes a mad rush to interrupt and stop Elaine's wedding - with one enormous and uncharacteristic burst of initiative. [He runs head-on toward an extreme depth of focus camera that appears to slow his pace, and makes him seem to be running in place and not getting anywhere.] He decides to try to halt the marriage from the church balcony, looking down through a pane of plate-glass (in a crucifixion image) as the ceremony concludes. He pounds on the glass, hopelessly calling out: "Elaine! Elaine! Elaine! Elaine!" as they exchange wedding vows. The bride finally looks up - startled - torn between Benjamin, her parents and her new, safe husband. The Robinsons react to his appearance at the arranged marriage:

Mr. Robinson: Who's that guy? What's he doing? I'll take care of him.
Mrs. Robinson: He's too late.

Elaine walks slowly to the back of the church, her eyes transfixed on Benjamin - and seduced by his brash, clear, and honest urge to have her. Mrs. Robinson and others make angry gestures toward him, but from his point of view, he can't hear them. Elaine chooses him, screaming out: "Ben!" Benjamin knocks Mr. Robinson to the floor, pushes the bridegroom back, and grabs newly-wed Elaine, as Mrs. Robinson confronts her daughter:

Mrs. Robinson: It's too late.
Elaine: Not for me.

Mrs. Robinson slaps Elaine twice across the face to bring her back to reality, but it doesn't work. Elaine and Benjamin run out of the church together, after he has grabbed a large golden church cross, using it first as a weapon to clear a path and then as a barrier for the large glass doors to prevent everyone from following into their world. With the glass door securely locked, they symbolically and literally hold back the forces of resistance by their act of rebellion.

Then, Elaine, still in her bridal gown, and Benjamin, grubby and unshaven, run to flag down and board a passing yellow municipal bus while giggling and laughing at their triumphant (but ultimately pointless) victory. They rush to the rear seat of the city bus and look out the rear glass window, amidst puzzling, stern and cold looks from the other elderly passengers of another generation. Oblivious to the other passengers in front of them, the two of them face each other and grin, but their victorious, self-satisfied moods begin to fade and disappear. Appropriately, The Sounds of Silence is reprised on the soundtrack. They ride in the final image staring silently ahead, uncharacteristically silent toward each other and not even looking at each other. Do they actually love or really care for each other? - probably not. [Their relationship is maybe not much different from the one Benjamin experienced with Elaine's mother in bed, and shortly, they both may fall back into the same world of their parents.]

They are traveling toward an unpredictable, ambiguous future. Now, what will happen, after their dramatic (and futile) escape? They are stunned and out of breath - very well aware that their futures are wide-open and very uncertain. Ben has won the object of his Holy Grail quest, but probably lost the love of his life. Elaine gratefully approves of her kidnapping, but remains apprehensive. The final image views them through the rear glass windows of the providential bus as it pulls away, separated from their families - and from each other.