CASE warns Cooper that Endurance is slipping toward Gargantua's pull. Cooper makes a quick decision to use Gargantua as a gravitational slingshot to propel the ship toward Edmunds' planet, but their proximity to Gargantua means more time will elapse on Earth. To shed weight, Cooper and TARS jettison themselves toward the black hole, so that Amelia and CASE can complete the journey. Slipping past the event horizon, Cooper and TARS find themselves inside a tesseract, which resembles a stream of bookshelves capable of peering into Murphy's bedroom at different periods in her life. Cooper surmises that the tesseract and wormhole were created to enable communication with Murphy, and that he was her "ghost" all along. Using the second-hand on the watch he gave her before he left, Cooper relays the quantum data Murphy needs to solve the gravitational equation.