There was a catch. Plan A was to solve the equation for gravity, allowing NASA to lift the giant space arks off the dying Earth. Plan B was to abandon Earth entirely, carrying 5,000 frozen human embryos to start a new colony on a new world. Professor Brand had lied to everyone. He knew Plan A was mathematically impossible without data from inside a black hole—data that could never be retrieved.

"I knew you'd come back," she whispered, her voice fragile. "Because my father promised me."

Now, with the Endurance crippled and fuel running out, they had one final chance: the last planet, Edmund’s. But to reach it, they would need to slingshot around Gargantua itself, a maneuver that would cost them years. Amelia suggested a radical idea: use the black hole’s gravity to their advantage. But Cooper had a different plan.

Cooper sat down to watch a backlog of video messages. His son, Tom, had grown up, gotten married, had a child, and buried that child. And then came Murph. She was now the same age Cooper had been when he left. Her face, hardened by anger and grief, appeared on the screen. "Dad," she whispered, tears in her eyes. "You said you’d come back. Today is my birthday. And you’re not here."

Cooper had no place in this future. His daughter told him to go. "No parent should have to watch their own child die," she said. "Go find Amelia."

Cooper was torn. Leaving meant missing his children’s lives forever. But staying meant they had no future. Promising Murph he would return, he piloted the Endurance into the wormhole, alongside a team: the professor’s brilliant daughter, Amelia; two scientists, Romilly and Doyle; and two robotic companions, TARS and CASE.

Decades earlier, a mysterious wormhole—a tear in the fabric of space-time—had appeared near Saturn. No one knew who placed it, but it was an invitation. Through that portal lay twelve potentially habitable worlds orbiting a supermassive black hole named Gargantua. Three of the worlds had sent back a "thumbs up" signal. The mission, Endurance , was to go through the wormhole, check those three planets, and find a new home for the human race.

The Tesseract collapsed, spitting Cooper back out into the solar system near Saturn. He had aged only a few years, but decades had passed on Earth. He was found, drifting in space. By the time he woke in a hospital on Cooper Station—a vast, cylindrical ark orbiting Saturn—he had missed everything. He was 124 years old. He learned that Murph had taken his data, solved the equation, and saved the remnants of humanity.