Cooper falls into the black hole, expecting to die. Instead, he is saved from spaghettification by "They." He finds himself inside a five-dimensional structure known as a . This structure appears as an infinite grid of Murph’s bedroom at different points in time.
Cooper realizes that "They" are actually future humans who have evolved to exist in five dimensions. They built the Tesseract so he could communicate with the past. He was the "ghost" Murph saw all along. He manipulates gravity to send binary messages to the young Murph, giving her the coordinates to NASA (starting the mission) and, later, sending quantum data collected by TARS inside the black hole to the adult Murph. plot for interstellar
With the Endurance crippled and resources gone, Cooper sacrifices himself, slingshotting the ship’s module (with the sleeping Amelia Brand) toward Edmunds’ planet while he plunges into Gargantua’s event horizon. This is where the plot abandons conventional space physics for metaphysical spectacle. Inside the black hole, Cooper finds a tesseract—a five-dimensional construct built by future hyper-advanced humans. Here, the linear flow of time becomes a physical dimension. Cooper can reach across decades, interacting with the “ghost” in Murph’s childhood bedroom. Cooper falls into the black hole, expecting to die