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In a not-so-distant future, cereal species are getting extinct one by one by
the blight, and sand storm happen regularly. Cooper, an ex-astronaut and now
farmer decodes a message appearing in his daughter Murphy's room as
gravitational anomalies, leading him to what is left of NASA. Scientists there
work in parallel on anti-gravity and on sending manned exploratory probes
through a wormhole that had appeared near Staturn fifty years earlier; plan A
is to make space stations and take humanity away from the surface into space
and plan B is to send frozen embryo to a suitable planet in the other galaxy.
Cooper is asked to travel through the wormhole to another galaxy, finding out
what happened to the three probes that are still emitting pings back to Earth.
Cooper leaves his children in the care of their grandfather, knowing that
because of relativity, they will age much faster than he will. In the other
galaxy, they have three planets to visit. On the first one, there is only the
wreckage of the probe, destroyed by gigantic waves and barely escape with
their lives, losing one crew member. On the second planet, they find a
survivor ,Mann, who tries to kill them to take their ship and escape back to
Earth. Cooper learns from him that he had faked the data about the planet
(it's not inhabitable) to attract rescuers and that anti-gravity cannot be
discovered without measurements taken from the inside of a black hole, and
that plan A is just a scam to get people working while plan B is applied.
Cooper and Brand manage to escape from the planet and save their orbiter from
Mann's wrong docking maneuvres that almost destroyed it. They then split,
Brand going to the third planet while Cooper jumps into the black hole. He
discovers there an environment when he can survive, showing a 2-dimension view
to his daughter's room and where he can travel time as a dimension of space.
He then understands he can send messages by generating gravitational
anomalies. He also sends the measurements taken from inside the blackhole by
his robot sidekick, leading his daughter to discover anti-gravity. His
environment then collapses and he's spit out of the wormhole. He eventually
wakes up in a space station years later, seing his now elderly daughter for
the last time. She convices him to go back and search for Brand, who is
implementing plan B on the last planet (that happens to be habitable).