Fermat's Room [2007, Spain, thriller, detective, DVD5]

After resolving a test with a sequence of numbers, four mathematicians are challenged by a mysterious man called Fermat to meet in an isolated place to resolve the greatest enigma ever. Each one receives a code name - Hilbert, Pascal, Galois and Oliva - and heads to a barn on an island. Inside the barn, they find a comfortable room, and soon their host arrives. They have dinner together and Fermat receives a phone call from the hospital, where his daughter in interned in coma. He asks to leave the place for one hour; however after his departure, the quartet finds that they are locked in the room. They receive a phone call with a mathematical riddle and given one minute to reply; soon they find that if they do not find the answer to the questions, the walls move and the room shrinks, pressed in by four Poseidon hydraulic presses. While responding the questions, they try to find Fermat's motive - why they have been gathered together to be killed.