Fermat's Room () is a 2007 Spanish thriller film directed by Luis Piedrahita and Rodrigo Sopeña. Three mathematicians and one inventor are invited to a house under the premise of solving a great enigma, and told to use pseudonyms based on famous historical mathematicians. At the house, they are trapped in a room. They must solve puzzles given by the host, who calls himself "Fermat", in order to escape the slowly closing walls of the room. Plot A stranger using the alias "Fermat" invites several people to attend a convention of the country's best mathematicians. To accept the invitation, each must solve a math puzzle. Upon receipt of the correct solution, each receives as an alias the name of a famous mathematician or philosopher; they are forbidden to reveal their true identities. Each is instructed to arrive at a specific place and time, alone and without a cell phone, to work on "the greatest enigma". At the appointed time, four individuals converge at a riverbank: a serious young man using the alias Galois, an older man using Hilbert, a self-effacing young man using Pascal, and a stylish young woman using Oliva. At dusk, a car on the far side of the river flashes its headlights. In the car they find a PDA with GPS coordinates and travel instructions. These direct them to an abandoned warehouse, where a back room is set up as an elegant parlor stocked with books and a large dining table set for five. An elderly man enters and introduces himself as Fermat. They socialize and discuss academia, mathematics, and puzzles. After dinner, Fermat receives a phone call about his daughter, whom he claims is in a coma at a nearby hospital. Mobile reception is poor, and Fermat is unclear about the meaning of the call. Insisting it might be dire news, he leaves hurriedly and forgets his coat. Fermat's wallet drops out of a pocket in the confusion. Pascal picks it up and notices a photo of a girl. The PDA displays a math puzzle, with a time limit of one minute. Hilbert, Oliva, and Galois work on the problem but exceed the deadline. Pascal calls it an old cliché and solves it easily. The walls contract when the deadline is exceeded. Pascal finds a sales order for four industrial presses. The group intuits that the presses are set to compress the room each time they