Interstellar begins sometime in the near future with the planet reeling from environmental disaster. War has reduced the population, and a crop disease called blight threatens to starve humanity to death. Joseph Cooper, a former pilot for NASA, and a widower, raises his two children with his father-in-law on his farm. A ghost haunts his daughter, Murphy, whom they call Murph. She thinks the spook lives in her room behind her bookcase. One day after an intense dust storm, a disturbance in gravity leaves a series of lines on the ground. Cooper investigates and realizes that the lines are coordinates.
Cooper and Murph follow the coordinates to a secret NASA facility. There they find artificially intelligent robots, a bunch of scientists trying to launch giant spacecraft, and Dr. Brand, Cooper’s former professor. They learn that a wormhole appeared mysteriously near Saturn some years ago. NASA sent a group of scientists through the wormhole to try and find habitable planets where they can relocate humanity. If they can’t relocate humanity by launching the entire facility into space, plan B is to restart the human race with a warehouse of embryos and a whole lotta love.
They plead with Cooper to pilot the spaceship that will follow up on the former scientists in the wormhole. He agrees, given the imminent threat the humanity on earth. He takes Murph home and breaks the news to her. She takes it poorly, and Cooper has to leave her crying in her room.
The crew consists of Cooper, Romilly, Doyle, and Dr. Brand’s daughter, Dr. Brand. They head for Saturn and are able to send and receive video messages back home. Murph refuses to talk to Cooper.
On the other side of the wormhole, the crew has to make a tough decision. They don’t have enough fuel to visit more than two planets. In addition, some of the planets have a larger gravitational pull and time will move more slowly for them on the planet than back at earth. Further complicating things is a large black hole nearby that can capture them with its gravity. The crew chooses poorly and lands on a large planet. The crew appears to be gone for a few short hours, but decades pass on Earth. Cooper returns to space realizing that he has missed all of his children’s childhoods.
The crew uses their last fuel to visit the planet of Dr. Mann, the NASA astronaut that inspired the missions through the wormhole. The crew finds Dr Mann, but soon learns that he faked signs of life on his planet in order to get rescued from his loneliness on the isolated frozen planet. Dr. Mann hijacks their ship and causes serious damage to the space station trying to dock.
Meanwhile, Murph has grown to be as assistant to the distinguished Dr. Brand. However, she discovers that plan A was always a lie and that Dr. Brand discovered long ago that they lacked the knowledge to launch the facility into space. She tells her dad this in a rare message to the space station.
Back on the space station, they surmise that if they could gather data from the black hole, they might figure out what they need to launch the facility into space and save the humans. Cooper decides to take one for the team and launches himself into the black hole with one of their robots, saving the Brand’s life.
In the black hole, Cooper finds himself suspended in space, in a physical representation of the space and time in Murph’s bedroom. He discovers that he is her ghost and that humans in the future have chosen Murph to save them by solving the mystery of launching the facility into space. Cooper provides Murph with the necessary data from the black hole to launch the facility into space and then he is ejected from the black hole and into the wormhole.
Cooper is discovered floating in space at some point distant in the future. He is taken to a space station where he meets Murph, now a very old woman. Murph is the heroine of mankind, having found the technology to save them from the dying earth. Murph moves on, and Cooper takes off on a mission to retrieve Brand, who is starting a colony on a distant but habitable planet.