Intro. The film begins by showing a not-so-distant future, in which the Earth is dying. Crops are being destroyed by a plague, dust storms fill the air, and humanity is increasingly desperate.
The protagonist, Cooper, was a NASA pilot, but now lives as a farmer with:
Murph, your intelligent and stubborn daughter
Tom, his eldest son
Donald, the father-in-law
Right at the beginning, Murph starts saying that her room is "haunted", because books fall off the shelf by themselves. Cooper, curious, begins to investigate this — and this little mystery will be the key to opening the entire story of the film.
One day, a dust storm covers everything, and when Cooper arrives home, he notices that the dust has formed a strange pattern on the floor of Murph's room... following this pattern, he discovers coordinates, which take him to a secret place.
This place is the hidden NASA, which still exists, but works in secret.
From there, the story begins in earnest.