Maria is waiting for Tony on the rooftop of her tenement building, expecting to hear of his peaceful intervention. In a short, lovely and enchanting dance sequence, she expresses her inner happiness by dancing around by herself on the rooftop. Chino appears with a bloody bruise on his cheek, visible when he steps into the light. Dismayed, Maria realizes there's been a fight, although "nobody meant for it to happen." She is feverishly curious about Tony's well-being. Chino yells at her: "He killed your brother!" She is stunned to learn of her brother's death, and numbed by the tragic turn of events. Maria can't believe that her boyfriend has killed her own brother. She prays in her bedroom before the Virgin Mary: "Make it not be true!...I will do anything. Make me die."

Tony climbs into her bedroom window - she pounds on his chest and collapses. He admits: "I tried to stop it. I did try. I don't know what went wrong. I didn't mean to hurt him. I didn't wanna. Riff- he was like my brother. When Bernardo killed him, Bernardo didn't mean it either...I thought you knew." Now that she knows he killed her brother in retaliation, she decides to forgive him and to steadfastly stand by him - she is incapable of hating him. She urges: "Stay with me. Don't leave me...Hold me...Tighter." Tony remains blinded and rebelliously-indifferent to their plight, believing and hoping that there is still "Somewhere" they can run away to and find peace together for their forbidden love:

Tony: It'll be all right, I know it. We're really together now.
Maria: But it's not us. It's everything around us.
Tony: Then I'll take you away where nothing can get to us - not anyone or anything.

Somewhere:

(Tony) There's a place for us, Somewhere a place for us
Peace and quiet and open air wait for us, Somewhere
(Maria) There's a time for us, Some day a time for us
Time together with time to spare, time to look, time to care, Someday
(Tony) Somewhere we'll find a new way of living
(Maria) We'll find a way of forgiving, Somewhere
(Tony and Maria) There's a place for us, a time and place for us
Hold my hand and we're halfway there
Hold my hand and I'll take you there
Somehow, Someday, Somewhere

Although some of the Jets gang regret the killings, an edgy and tense Action vows to get even: "They're gonna pay, them stinkin' Sharks." Ice urges everyone to "play it cool" until the crisis blows over:

Now you all better dig this and dig it good. No matter who or what is eatin' you, man, you show it and you are dead. You are cuttin' a hole in yourselves for them to stick in a red hot umbrella and open it. Wide. Man, you wanna get past the cops when they start askin' you about tonight? You wanna live in this lousy world? You play it cool.

Together, they sing/dance "Cool," a finger-snapping, tense, beat-oriented tune in a deserted delivery van parking garage with a low ceiling. The Jets plan to find Tony before Chino does - he's hunting for Tony with a gun.

After sleeping together in her bedroom, Maria and Tony make plans to "go so far away they'll never find us," using "getaway money" from Doc. They will escape the surrounding hatred and find a less violent, hateful world to live in. Tony decides to hide out in the cellar of Doc's store, until she can get word to him. Anita discovers that they remain lovers despite the fact that Tony killed Maria's brother:

Maria: Now you know.
Anita: And you still don't know. He is one of them.
Maria: No, Anita.
Anita: Yes.

Still grieving the death of her boyfriend Bernardo, Anita insists that Maria forget loving her enemy and "stick to your own kind." She chides Maria with a song: "A Boy Like That."

A Boy Like That:

A boy like that who'd kill your brother
Forget that boy and find another
One of your own kind, stick to your own kind
A boy like that will give you sorrow
You'll meet another boy tomorrow
One of your own kind, stick to your own kind
A boy who kills cannot love, a boy who kills has no heart
And he's the boy who gets your love
And gets your heart, very smart Maria, very smart
A boy like that wants one thing only
And when he's done he'll leave you lonely
He'll murder your love, he murdered mine
Just wait and see, just wait Maria, just wait and see

Faithful to Tony, Maria declares her love in another song, "I Have a Love":

I Have a Love:

Oh no Anita, no, Anita, no, it isn't true, not for me
It's true for you, not for me
I hear your words and in my head I know they're smart
But my heart, Anita, but my heart knows they're wrong
You should know better, you were in love
Or so you said, you should know better
I have a love and it's all that I have
Right or wrong, what else can I do?
I love him, I'm his, and everything he is I am too
I have a love, and it's all that I need
Right or wrong, and he needs me too
I love him, we're one, there's nothing to be done
Not a thing I can do, but hold him, hold him forever
Be with him now, tomorrow and all of my life
(Maria and Anita) When love comes so strong
There is no right or wrong
Your love is your life

Anita is convinced of Maria's true love for Tony - "right or wrong." Lieutenant Schrank, in the midst of an investigation of the killings of Riff and Bernardo, arrives to ask Maria about the identity of the "wrong boy" she danced with in the gymnasium - an incident that stimulated conflict between the gangs. Cleverly, she uses disguised language to send Anita to Doc's store to take a warning message to Tony: "Tell him I have been detained and can't get there right away." Anita enters Doc's store to deliver the important message - but she is mercilessly insulted and taunted by the vengeful Jets as a "greaseball." Smoke is blown in her face, and she is not permitted to pass because "she's too dark." The Puerto Rican is exasperated by their obtuse ignorance: "Don't you understand? I want to help." Labeled as "Bernardo's tramp, Bernardo's pig, lyin' spic," they suspect she is trying to find Tony's whereabouts to help Chino locate him. They surround her, toss her around, taunt her like a wild bull in a bull-ring, and finally simulate a rapist's assault. Doc's return, with cash for Tony in his hands, ends their vicious teasing.

In an untimely twist of fate, her message of reconciliation between the two lovers fails to get through. Spitefully, she lies and tells them that Maria's ex-boyfriend Chino has killed Maria in anger:

Anita: Bernardo was right. If one of you was lying in the street bleeding, I'd walk by and spit on you.
Action: Go on and go. Don't tell Chino that Tony's hidin' in the cellar.
Anita: Don't you touch me! I got a message for your American buddy. You tell that murderer that Maria's never going to meet him. You tell him that Chino found out about them and shot her. She's dead.
Doc: When do you kids stop? You make this world lousy.
Action: We didn't make it, Doc.
Doc: Get out of here.

In the cellar with Doc, Tony is wildly optimistic about his future with Maria: "Do you know what we're going to do in the country, Maria and me? We're gonna have lots of kids. And we're gonna name 'em all after ya." But Doc slaps him to "Wake up!" and tells him about the rumored death of Maria: "There is no Maria, Tony." Not wanting to live without Maria, Tony bursts out of his hiding place to challenge Chino: "Come and get me too, Chino." He welcomes his own death.

Devastated, Tony races and roams through the desolate streets, crying out for Chino to kill him: "Come on Chino, get me too...There's nobody here but me...I'm waitin' for ya." Tony learns the truth that Maria is alive too late - dressed in red, she is on the other side of the chain-fenced playground. She rushes joyfully toward him to embrace him, but he has already been spotted by Chino. Just before they reach each other's arms in a tiny spot of light (and in the only area of dry pavement) on the playground, he is shot by Chino as revenge for Bernardo's death (and as retribution for being thwarted in his love for Maria).

The remaining members of both gangs gather after the single gunshot. Maria grieves as she holds the dying Tony in her arms:

Tony: I didn't believe hard enough.
Maria: Loving is enough.
Tony: Not here. They won't let us be.
Maria: Then we'll get away.
Tony: Yeah. We can?
Maria: Yes.
Tony: We will?
Maria: Yes. (singing) Hold my hand and we're halfway there. Hold my hand and I'll take you there. Somehow, someday, some...

She mourns his passing and commands the two gangs that threaten more violence: "Stay back!" Walking in between them as she wields Chino's deadly weapon, she accuses all of them of being responsible for Tony's senseless death - contributing factors are societal intolerance, racial antagonism, misunderstanding, mistrust, and the fermentation of hatred. She lectures at them about how hate breeds more hate:

How many bullets are left, Chino? Enough for you, and you? All of you. You all killed him! And my brother, and Riff. Not with bullets and guns - with hate. Well, I can kill too because now I have hate! How many can I kill, Chino? How many and still have one bullet left for me?

She falls to her knees, weeping. A red light circulates over all of them from the approaching police car's cherry-top. She screams at Lieutenant Schrank as he walks toward her beloved's body: "Don't you touch him!" She tenderly kisses the lips of Tony one last time, and expresses her love for him in Spanish:

Te adoro, Anton.

The struggle of Maria and Tony to love each other in the face of opposition ends on a hopeful note. The two gangs, confused, stunned, ashamed and sobered by the unnecessary triple killings, finally put aside their enmity. As some of the Jets struggle to bear Tony's body away, a few of the Sharks assist them. Together, they solemnly carry him down the street, with Maria following. For once, the opposing groups are united and reconciled - by the heart-breaking tragedy.

The imaginative end credits, displayed as chalk-marked graffiti on inner city brick walls and surfaces, were designed by Saul Bass.