He pushed at one of the objects, and it shifted incrementally. He pushed harder, and then harder until finally it popped through and dropped out of sight.
Peering through the gap he saw her. She was ten and her hair was wet. She had a towel around her neck, and she was just turning, startled by the book falling.
“Murph?” he called. “Murph?”
But she didn’t react. She just stood there, gazing at the shelves, at the book on the floor, which he could no longer see. Then she came cautiously toward the shelf and bent down. When she came up she was holding a broken toy.
The lunar lander.
In the twilight, Murph turned the lander model in her hand, remembering, wondering. Outside, Getty was sounding more frantic. But she felt somehow, there was something here.
Cooper watched his ten-year-old daughter examine the broken model.
“Murph!” He tried again. “Murph!”
But she still didn’t hear him. She turned and left the room, and he knew where she was going—to the breakfast table, where he would chastise her for being unscientific and not taking care of “our stuff.”
Desperately, he looked around and realized that he was in something like a cube, and each wall of the cube looked into Murph’s room from a different angle, as if the room had been turned inside out, reversed, and put back together. And it wasn’t just the one room, the one bookshelf. He saw now the matrix of light held multiple iterations of the room, maybe infinite, tunnels and passages going in every direction, framed, held together by the light streaming from the books, the walls, the objects in the room.
It was disorienting, and he wished Romilly was there to explain to him what was going on. He had to be operating in more than three dimensions, but since his mind was only built to handle three—well, he figured it was doing its best.
He was still in free-fall. By floating around and using his thrusters, he could effectively move to each iteration of Murph’s room, so he pulled himself to the next one and punched out two more books.
Through the resulting gap he saw an empty bedroom. It didn’t stay empty for long, though. The door opened and—well—he walked in. His younger self, looking bothered about something. A moment later, Murph entered as well.
Cooper slammed into the books, kicked another out, furiously determined to get their attention.
Murph rubbed her hand across the old desk, remembering all those years ago when she had pushed it in front of the door, how angry and sad she had been. She reached for the chair, too, and tilted it back.
Cooper watched Murph put the chair on top of the desk, completing her barricade of the door. A moment later, he saw it move a little as someone—no, not someone, but him, the earlier him—began to nudge through.
“Just go,” Murph said. “If you’re leaving—just leave now.”
Cooper spun around to another wall, and saw his earlier self on the other side of the door.
“Don’t go, you idiot!” he yelled, as the other Cooper closed the door. Going to let Murph cool off. Precisely the wrong move. “Don’t leave your kids, you goddamn fool!” he shouted.
He began punching at the walls with everything in him, but not blindly. He knew what to do.
“S,” he said. “T…”
Murph was watching now. She didn’t look scared. She looked amazed, excited, interested.
“A,” he grunted. “Y.”
He stopped to catch his breath, then watched in frustration as his earlier self reached through the cracked door and around, to lift off the chair so he could push back the desk and enter the room.
“Stay, you idiot!” he yelled. “Tell him, Murph! Stay…”
He watched numbly as it played out, just like before. He gave her the watch. She hurled it across the room.
“Murph,” he pleaded. “Tell him again! Don’t let him leave…”
He broke down and began to cry, the sheer frustration of having to watch it all, and not be able to do anything. It was way too much to handle. Once again, he wondered if he was dead. If this was Hell.
Because it damn sure felt like it.
Murph picked up her old notebook and paged through it, stopping when she reached her Morse code interpretation of the gaps in the books.
Stay.
She looked up from the notebook back to the books, and felt something almost like a rush of wind go through her, as if some hidden place had suddenly been opened. She went to the shelves, and began pulling books out.
The smell of burning corn drifted up from downstairs, where the door stood open for her.
“Murph,” Cooper sobbed. “Don’t let me leave.”
But his earlier self turned, heading for the door.
“Stay!” he screamed, slamming the books with all of his might. One dropped, and the earlier Cooper turned. Looked at it…
And left.
Cooper put his head against the books, weeping.
Murph stared at the gaps she had made in the books, and then back at her notebook. Her throat tightened.
“Dad,” she said. “It was you. You were my ghost…”
Tears started, not from pain or anger or sadness, but from the greatest joy she had felt in many, many years. He hadn’t abandoned her. He had tried. He had been her ghost all along.
Cooper was still crying when he heard his name. He turned, but there was no one there, and he realized the voice had come from his radio. He also recognized the voice.
TARS.
“You survived,” Cooper said.
“Somewhere,” TARS agreed. “In their fifth dimension. They saved us.”
“Who’s ‘they’?” he asked. “And why would they help us?”
“I don’t know,” TARS admitted, “but they constructed this three-dimensional space inside their five-dimensional reality, to allow you to understand it.”
“It isn’t working!” Cooper exploded.
“Yes, it is,” TARS said. “You’ve seen that time here is represented as a physical dimension. You even worked out that you can exert a force across space-time.”
Cooper frowned, trying to understand. And then, suddenly, he did. The streams of light from the books were paths. Through time. Showing where each thing in Murph’s room had come from and where it was going. And the force he was exerting…
“Gravity,” he said. “To send a message…”
He looked around the infinite tunnels, the infinite Murphs, the lines from the books, the shelves, everything in the room going off as far as he could see in any and every direction.
“Gravity crosses the dimensions, including time,” he said.
When he pressed an icon on a control panel, it wasn’t the icon that made the ship move. It was just something that translated his intention to the mechanisms that could actually start the ship. Similarly, although it felt as if he was punching the books out with his fists and feet, in fact that was not possible. His physical body, this physical body was not—could not be—in the past.
But gravity could. Like TARS said, gravity cut across and through all of the dimensions. When he punched at one of them, what he was really doing was sending a pulse through space-time, a gravitic surge that was responsible for moving the books.
In other words, he was the source of a gravitational anomaly, and “they” had given him control of it in the most natural way possible—by making his sense of self, his sense of body, the controller. By giving images—icons—that he could understand and exert that force upon.