A group of elderly people are giving interviews about having lived in a climate of crop blight and constant dust reminiscent of The Great Depression of the 1930's.
The first one seen is an elderly woman stating her father was a farmer, but did not start out that way.
The scene changes. The setting is an unspecified part of the rural Midwest. We are introduced to a farmer and widower named Joe Cooper (Matthew McConaughey). He is a college-educated former NASA test pilot and engineer who was forced to give up his occupation to farm, living in a run down farmhouse, presumably owned by his father in law.
They farm corn, with wheat no longer available and okra just now having become extinct due to blight. We see no animal life. It is the year 2065 in eastern Colorado. More than half the world's population has been decimated from famine and America has been reduced to a struggling agrarian society.
Technology has come to a standstill for the past 40 or so years, with automobiles no longer produced and a computer laptop is a luxury item. There is no military or wars anymore. At a certain age, kids are tested to determine what occupations they will have to take to help humanity survive. In school, it is taught that the US going to the moon in 1969 was a hoax to drive the Soviet Union into bankruptcy and win the Cold War.
Cooper's family consists of Joe's 65-year-old father-in-law, Donald (John Lithgow), his 15-year-old son Tom (Timothée Chalamet), and 10-year-old daughter Murph (Mackenzie Foy). Donald was born at the end of the 20th or beginning of the 21st century and fondly recalls times when technology was constantly changing and new gadgets being invented. He is a down-to-Earth man who takes care of the household duties and gets along well with Cooper.
The two of them sit on the porch drinking beer in the evening and philosophize about the condition of the world and how things should be. Joe's son Tom is a boy of average intelligence already being ruled out to be a farmer by the school administration, since a college education is now something only a very small percentage those will enjoy the privilege of.
His daughter Murph is a feisty and highly intelligent girl whom Cooper is very close to and who shares his affinity with space and science.
She believes her room is haunted by a ghost because books keep falling off her shelves and a lunar ship model was just knocked over.
The Cooper family lives a pretty simple life and have a rare treat of attending a game of a supposedly major league baseball team at a local ball field similar to what the little league play on today. His father in law is unimpressed at the amateurishness of the players and having only popcorn for refreshments and no hot dogs. An approaching dust cloud interrupts the game reminding them of the grim world they live in, and ends it prematurely.
The Cooper family makes back to the farmhouse during the dust storm and Murph's bedroom did not have the window closed and the dust settled into perfect lines on the floor.
Cooper spends the entire night studying the lines and Cooper thinks the lines are binary code and coordinates for a place he feels the need to find and uses a map.
He spends the next day driving to the Rockies and his daughter sneaks into the truck to come with him. Soon after arriving at his final destination, Cooper is apprehended and tasered into unconsciousness by a strange looking robot called TARS.
It turns out he is in the best-kept secret in the world, a bunker, and meets his old boss from NASA, an Englishman named Dr. John Brand (Michael Caine), plus his beautiful young daughter, Amelia Brand (Anne Hathaway). Nobody is convinced that Cooper just stumbled into the place by accident and Dr. Brand believes a force brought Cooper there. The compound Cooper found is actually the remnants of NASA, inhabiting the facility in secret and no longer funded by the government because of the scarcity of resources.
There is a space mission leaving soon to go through a wormhole of unknown origin near Saturn that will take them to three potentially habitable planets, two of them orbiting a supermassive black hole named Gargantua; a large black sphere about the size in diameter of Earth's sun but which has a solar mass of about 50 million Earth suns. Ten years earlier, 12 individual astronauts were sent out through the wormhole in 12 different ships, but only three (Miller, Mann, and Edmond's) activated the thumbs up beacon, all of whom are at three planets.
At the moment, NASA has nobody to pilot the spacecraft and at the last minute they want Cooper to go, despite his family responsibilities. The bunker itself is actually a centrifuge, which is projected to become something else later on. The mission has two plans: Plan A is to get the centrifuge into orbit as a space station and rescue a large number of people; this requires Dr. Brand to solve the equation that will allow the scientists to overcome gravity and get the centrifuge into orbit. Plan B is to colonize the most habitable of the three planets along with a bunch of frozen embryos to repopulate the species.
Dr. Brand assures Cooper the Earth is dying and humanity doesn't have much longer and that he needs to pilot the craft and explore, lest his family and the rest of the world all die soon. Cooper is very reluctant, because he's barely left Earth's atmosphere, but Brand reassures Cooper the twelve astronauts sent on the mission never even left the simulators beforehand. The next day, Cooper and Murph return to the farmhouse, his daughter is extremely upset with him for choosing the mission.
That night Cooper and Donald are sitting on the porch drinking beer and Cooper reminding Donald once again of the futility of staying and the conditions they live in. Donald assures Cooper he's doing the right thing, but needs to set things right with Murph.
The next morning, Cooper does his best to comfort a sobbing Murph and promises to come back to her and that they might even be the same age when he returns, giving her a wristwatch to compare time. Murph refuses his assurance and that her bookshelf is communicating with her in Morse Code to "stay".
Despite her pleas, Cooper won't back down and one more book falls down before he leaves, but Cooper disregards it.
Cooper leaves and says goodbye to Tom and Donald and while he's driving away, Murph storms out the front door wanting to see him one last time, but it's too late.
The space shuttlecraft rockets away from Earth at high speed with Cooper, Amelia Brand, Dr. Doyle (Wes Bentley), Dr. Nikolai "Rom" Romilly (David Gyasi), and the TARS and CASE robots on board.
Doyle and Romilly are two scientists that were in the conference room at NASA during the meeting with Cooper.
When the spacecraft leaves the atmosphere, everything goes quiet all of a sudden, except the inside.
The ring shaped Endurance is up ahead and they dock with it, which has all their needs for space travel.
The Endurance is leaving Earth and they bid farewell to a spinning Earth and have to look forward to the lonely, claustrophobic, and potentially dangerous reality of space
They put themselves in a plastic-covered water cryosleep bed for the two-year journey to Saturn.
Dr. Brand makes a trip in Cooper's old 2010 Dodge ram truck to deliver the vehicle back to the homestead and give a tape recorded message from Cooper to his family.
Murph appears hoping her father is home, but angrily storms back into the house. Donald tells Dr. Brand about how Murph is making fools out of her teachers, but Brand tells Donald maybe she'll eventually make a fool out of him.
Two years later: the Endurance is orbiting Saturn and Cooper is out of cryosleep, reviewing video messages.
His son Tom tells him he's doing okay and Donald says hi, telling Cooper that Murph still refuses to talk to him.
The Endurance crew come upon the wormhole, which resembles a plasma globe and will provide a quick channel for the crew to reach the three planets in the next galaxy.
The crew take off for the rough ride, (a la 2001 infinity) and come to their first mission, Miller's Planet.
During the time through the wormhole, Amelia reaches out and feels she touched someone's hand.
They find themselves in a region of space around 10 billion light years from planet Earth.
They decide to head first to Miller's planet, intending to stop there only briefly as its close proximity to Gargantua causes severe gravitational time dilation with each hour spent on the surface costing seven Earth years.
Cooper, Amelia, Doyle, and the robot CASE decide to risk themselves and intend to be in and out of there in just minutes to survey while Romilly remains on the Endurance to study the black hole and get quantum data from it.
When they land, all they find is shallow water and wreckage of Miller's ship, who apparently died and had arrived just an hour or two earlier, even though she sent the thumbs up beacon on Earth 10 years before.
The crew think there are mountains in the distance that turn out to be giant tsunami waves.
Brand becomes trapped under the Miller wreckage and has to be rescued and carried back by CASE.
Doyle is drowned, and the ship is flooded and won't be able to make it out for another hour, costing them years.
Cooper is frustrated at Brand, but forgives her mistake.
After the engines are mostly emptied of water, Cooper fires them up and just manages to escape the next tidal wave and fly off the surface. Cooper and Brand make it back to the Endurance to find an aged and gray Romilly in a robe -- 23 Earth years have passed and Romilly has spent most of the time waiting with a couple of stretches in cryosleep. It is now about the year 2090 on Earth. They are all beyond crushed, but Brand is relieved to know her father is still alive and well. They are receiving messages from Earth, but unable to transmit out. Cooper reviews all the videos and breaks down looking at 23 years of recorded videos and sees before his very eyes his 17-year-old son Tom showing a picture of what he believes is the right girl for him.
In the next video, Tom (now played by Casey Affleck) introduces to Cooper to his grandson Jesse. In the next video, a now beaten and aged 40-year-old Tom reveals that Donald died a week ago and is buried next to Jesse and that he believes Cooper to be missing or dead and needs to let him go. Then afterwards an apparent live recording comes from Murph (now played by Jessica Chastain). After 25 years of silence, a still stubborn and saddened Murph tells off her father for not fulfilling the possibility of being back because she is now 35 years of age, which is the same age he was when he left Earth. It's like a knife has been plunged into his heart and he feels he has betrayed her badly and has no way to communicate back with her.
On Earth, Murph stops recording the video. She is now working for Dr. Brand and living in the NASA bunker, who is now about 90-years-old and confined to a wheelchair. Brand is still trying to solve the incomplete gravity equation to get Plan A rolling and is reassuring Murph that the crew of the Endurance are receiving their recorded messages, but the crew can't transmit out.
Now that the Endurance crew have recovered emotionally from Murph's video, they debate whether to visit Mann's planet or Edmond's planet, because they only have enough fuel to visit one of them before they head back to Earth.
Brand wants to visit Edmond's Planet because his planet appears to be the better prospect, but Cooper wants to visit Mann's because he's still transmitting his beacon.
On Earth, Murph returns to the old Cooper homestead with her brother Tom, a farmer. He has just torched a third of his crop because of blight, which is spreading. He now has his old neighbor's crop to cultivate since the neighbor moved or died. They believe the farm will soon produce nothing.
She has dinner of corn soufflé and corn-on-the-cob with Tom, his wife Lois (Leah Cairns), and son Coop. She discovers Coop has a bad cough. They want her to stay the night, but she refuses because of bad memories from her childhood.
Murph is aware that the nitrogen levels in the air are taking their toll more and more each day on their son.