EXT. GARGANTUA - DAY

A black dot appears, rushing towards us to become a dark sphere. We plunge through it in silent darkness - a white sphere races towards us.

Just as the wormhole was a spherical hole, these spheres are holes within holes... we are dropping through a four-dimensional rabbit hole - light/dark/light/dark/light/dark with blinding rapidity - the frequency almost speaking. Cooper hangs on for dear life --

COMPUTER VOICE (O.S.): FULL CELL OVERLOAD. DESTRUCTION IMMINENT. INITIATE EJECTION.

Cooper is launched out of Ranger 2, which explodes, and, pulled to one side, misses a white hole - plunging instead towards a smaller glass-like sphere -

Cooper slows as he falls towards this sphere, reminiscent of the wormhole, but the light within is not stars but an infinity of world lines -- (paths of objects through spacetime)

Cooper plunges into the world sphere...

As he falls his single world line stretches behind him - the infinite futures of his world line splitting ahead to all the different possibilities of spacetime --

Cooper himself is now like a ring being pulled down a cone of fabric. He stares at the ordered chaos of world lines...

As he slows his past and future world lines break up so they become like infinite reflections in parallel mirrors...

Cooper's world line drops into a small, square tunnel--

INT. THE TESSERACT - CONTINUOUS

Tight enough to feel blindingly fast at first, but Cooper (and his infinite others) is actually slowing... Cooper desperately reaches out, knocking the sides of the tunnel, trying to slow himself - grappling - kicking "bricks" out of the "walls". He finally stops. Looks around in the sudden calm, floating, catching his breath. He reaches out to the tunnel wall - confused -
Each "brick" is tightly packed paper... pages... books - as seen from behind a shelf...

Cooper pushes against a book - it moves slightly. Cooper pushes, harder and harder and harder -

The book drops out of sight, revealing -

Murph, aged ten, wet hair, towel around her neck, turns, startled by the book falling from her shelf.

COOPER: Murph? Murph?

She can't hear him...

INT. MURPH'S BEDROOM - MORNING

Murph (ten) stands there, startled, staring at the bookshelves. At the book on the floor, a broken toy beside it...

INT. MURPH'S BEDROOM - TWILIGHT

Murph (forty) looks at the bookshelves, remembering...

INT. THE TESSERACT - CONTINUOUS

Cooper watches Murph (ten) cautiously approach - she crouches. Picks something up -

INT. MURPH'S BEDROOM - TWILIGHT
Murph (forty) turns the lunar lander in her hands. Thinking.

INT. MURPH'S BEDROOM - DAY

Murph (ten) stands up holding the broken lunar lander...

INT. THE TESSERACT - CONTINUOUS

Cooper watches Murph (ten) examine the two pieces of the lunar lander model -

COOPER: Murph! Murph!

She turns... leaves the room... Cooper floats there, staring. He looks around - each "wall" of the tesseract is a different view of Murph's bedroom, so that by rotating he can effectively orbit her room...

He claws his way down to the next book wall. Punches out two books-

Murph's bedroom, empty. The door opens, Cooper's earlier self is standing there, staring at the room, perturbed. Murph (ten) joins Cooper, staring at the empty room...

Cooper lashes out at the book - kicks a book out - spots -

Murph (ten) closes her door, crying, sliding the desk in front -

INT. MURPH'S BEDROOM - TWILIGHT

Murph (forty) feels the desk. She puts her hand on the back of the chair, tilts it slightly, remembering -
INT. THE TESSERACT - CONTINUOUS

Cooper watches Murph (ten) put a chair on top of the desk. The earlier Cooper nudges the door open -

INT. MURPH'S BEDROOM - EVENING

Murph (ten) sees the door nudging against the desk and chair -

MURPH: Just go. If you're leaving - just leave now.

INT. THE TESSERACT - CONTINUOUS

Cooper, the frustrated observer, spins around to see his earlier self nudging the door -

COOPER (to his earlier self): Don't go, you idiot!

His Earlier Self shuts the door...

COOPER: Don't leave your kids. You goddamn fool.

Cooper punches out books with all his strength -

COOPER: S... T...

Murph (ten) is watching, no longer scared, fascinated -

COOPER: A... Y...

Cooper stops. Catches his breath. Waits... Earlier Cooper lifts the chair off the table to enter. Cooper watches his earlier self, frustrated -

COOPER: Stay, you idiot! Tell him, Murph! Stay...

As before, Cooper gives Murph the watch... Murph throws the watch and turns away...

COOPER: Murph, tell him again! Don't let him leave...!

INT. MURPH'S BEDROOM - TWILIGHT

Murph (forty) picks up the notebook. Opens it. Finds the word "STAY"... looks up at the book, realizing...

INT. THE TESSERACT - DAY

Cooper is crying with frustration...

COOPER: Murph, don't let me leave...

Cooper watches as his earlier self heads to the door -

COOPER: STAY!!

Cooper smashes a book from the shelf with all his might - his earlier self turns back. Looks at the book. Then leaves. Cooper rests his head against the books, sobbing.

INT. MURPH’S BEDROOM - TWILIGHT

Murph (forty) lowers her notebook, moves to the bookshelves, in awe…

MURPH: Dad… it was you. You were my ghost…

She is crying. Joyful.

INT. THE TESSERACT - DAY

Cooper sobs at the back of the books. Lost…

TARS (over radio): Cooper?

Cooper, startled, turns. Tars is not there.

COOPER: You survived.

TARS (over radio): Somewhere. In their fifth dimension. They saved us…

COOPER (frustrated): Who’s “they”? And why would they help us?

TARS (over radio): I don’t know, but they constructed this three-dimensional space inside their five-dimensional reality to allow you to understand it…

COOPER: It isn’t working!

TARS (over radio): Yes, it is. You’ve seen that time is represented here as a physical dimension - you even worked out that you can exert a force across spacetime -

COOPER (realizing): Gravity. To send a message…

Cooper looks around the infinite tunnel, infinite Coopers.

COOPER: Gravity crosses the dimensions - including time 0

Cooper thinks… He pulls himself up to a different wall, starts counting books…

COOPER: And you have the quantum data, now -

TARS (over radio): I’m transmitting it on all wavelengths - but nothing’s getting out…

COOPER: I can do it -

Cooper hits a book’s world line, sending a wave…

TARS (over radio): Such complicated data… to a child…

COOPER: Not just any child.

INT. MURPH’S BEDROOM - TWILIGHT

Murph (forty) stands there, looking at her old notebook - the page that says “STAY”

GETTY (O.S.): Murph?! Come on!

She looks around the room, searching for an answer…

EXT. THE TESSERACT - DAY

Cooper watches Murph (ten) looking out the window…

TARS (over radio): Even if you communicate it here, she wouldn’t understand its significance for years…

Cooper is seized by a sudden anger -

COOPER: Then figure something out! Everybody on Earth is going to die!

TARS: Cooper, they didn’t bring us here to change the past.

Cooper hears something in this -

COOPER: We brought ourselves here…

Cooper pushes off, looking through the gaps in the books. Murph’s bedroom, full of dust in the dust storm…

COOPER: Tars, feed me the coordinates of NASA in binary…

Cooper is in the room now, drawing a pattern in the dust…

Cooper watches Murph (ten) burst into the room. Murph stops and stares at the dust as Cooper’s Earlier Self comes in past her, slams the window shut - sees the pattern of dust…

INT. MURPH’S BEDROOM - TWILIGHT

Murph (forty) runs her finger along the dust of the windowsill… She turns to look around the room. Frustrated.

MURPH: Come on, Dad. Is there something else here…?

INT. TESSERACT - CONTINUOUS

Cooper looks up from the floor -

COOPER: Don’t you see Tars? I brought myself here. We’re here to communicate with the three-dimensional world. We’re the bridge…

Cooper moves to another iteration of Murph’s room. Murph (ten) jumps up - grabs the watch, runs out the door…

INT. MURPH’S BEDROOM - TWILIGHT

Murph (forty) looks at the watch, remembering. The second hand twitches. She drops the watch back into the box…

INT. TESSERACT - CONTINUOUS

Cooper pushes himself along the world line of the books…

COOPER: I thought they chose me - they never chose me - they chose Murph.

TARS (over radio): For what?

COOPER: To save the world!

Murph (ten) comes back into her bedroom, sobbing. She is holding the watch. She puts it on the shelf.

INT. MURPH’S BEDROOM - TWILIGHT

Murph (forty) puts the box back on the shelf. Sighs…

INT. TESSERACT - CONTINUOUS

Cooper races faster and faster down the world lines.

COOPER: “They” have access to infinite time, infinite space…

Cooper gestures at the infinities in all directions…

COOPER: But no way to find what they need - but I can find Murph and find a way to tell her - like I found this moment -

TARS (over radio): How?

COOPER: Love, Tars. Love - just like Brand said - that’s how we find things here.

TARS (over radio): So what are we here to do?

Cooper looks around the tesseract. The watch sits there on the shelf for as long as he can see…

COOPER: The watch. That’s it. She’ll come back for it -

TARS: How do you know?

COOPER: Because I gave it to her. We use the second hand. Translate the data into Morse and feed it to me.

Tars starts to transmit. Cooper grabs the second-hand world line - starts to manipulate it, sending waves down the world line…

TARS: What if she never came back for it?

COOPER: She will. She will… I feel it…

The second hand is flickering back and forth…

INT. MURPH’S BEDROOM - TWILIGHT

Murph (forty) turns to leave…

GETTY (O.S.): Murph, he’s coming!

She pauses. Goes back to the box - reaches in, pulls out the watch… staring at it… wondering…

GETTY (O.S.): Murph?! Murph?!

EXT. FARMHOUSE - TWILIGHT

Getty is holding a tire iron, watching Tom’s truck approach. Lois and Coop stare, fearful, from the truck…

Tom approaches, black from soot…

Murph bursts out of the house… right up to Tom…

MURPH: Tom, he came back… he came back…

TOM: Who?

She holds up the watch…

MURPH: Dad. It was him. All this time… it was him. He’s going to save us…

Close on the second hand of the watch, flicking back and forth -

INT. PROFESSOR BRAND’S OFFICE - DAY

Murph furiously transcribes the movements of the second hand -

INT. CORRIDOR, NASA - LATTER

Murph, papers in hand, runs down the corridor, bumps into Getty - doesn’t stop…

INT. LAUNCH FACILITY - CONTINUOUS

Murph runs to the railing of the catwalk above the enormous construction, looks down at the thousands of workers below. Getty comes out after her, curious. She looks at him, then shouts out to the enormous space…

MURPH: EU-RE-KA!

She turns to Getty - grinning.

MURPH: Well, it’s traditional.

She throws her paper out over the railing-

MURPH: EUREKA!!

Workers look up to see her papers flitting down…

EXT. THE TESSERACT - DAY

Cooper looks out at the world line of the watch, of Murph, as it leads out into infinite complexity…

COOPER: Did it work?

TARS (over radio): I think it might have.

COOPER (hopeful): Why?

TARS (over radio): Because the bulk beings are closing the tesseract…

Cooper looks out to the distance - it is rapidly approaching, world lines becoming world sheets, becoming bulks…

COOPER: Don’t you get it, yet, Tars? “They” aren’t “beings”... they’re us... trying to help… just like I tried to help Murph.

TARS (over radio): People didn’t build this tesseract -

COOPER: Not yet… but one day. Not you and me but people, people who’ve evolved beyond the four dimensions we know…

The tesseract expansion into five dimensions is almost upon them - Cooper braces himself -

COOPER: What happens now?

BAM - he is swept up in the expansion like a tiny leaf on a churning wave. Cooper flies through the expanding cosmos, past planets, orbiting stars, which become atomic particles, which become matter, becoming stars…

Cooper approaches a glassy tube. Inside is the old, undamaged Endurance. As Cooper looks in from the bulk he sees: Brand, strapped in, Doyle opposite, traversing the wormhole for the first time…

Cooper reaches for Brand… She sees something, reaches up - their hands would touch if they weren’t in different dimensions, her fingers distorting the spacetime of the wormhole - he screams and we...