Fermat's Room (La Habitación De Fermat) Review

Four mathematicians walk into a room... It sounds like the set-up for a cheap joke, but when that room turns out to be a riddling deathtrap like the one in Vincenzo Natali's Cube (1997) or the original Saw (2004), then the four (and we along with them) are thrown into something altogether more gripping and claustrophobic.

Of course, while mathematicians are no less cutthroat than any other community when the stakes are high, the very nature of their calling makes them better than most at calculating - and manipulating - the odds with extreme elegance, while a professional leaning towards insanity (witness A Beautiful Mind) practically guarantees that the game will follow an unpredictable course. So with their feature debut Fermat's Room, writing-directing team Luis Piedrahita and Rodrigo Sopeño have hit upon a winning thriller formula that they follow through to its logical conclusion with precise economy and not a little head-twisting delirium.

Summoned by written invitations-cum-challenges from a stranger calling himself Fermat, the four mathematicians assemble at a remote location where they are to be presented with "the most ingenious, unedited enigma ever set out" which they can discuss using assigned pseudonyms. 'Galois' (Alejo Sauras) is a cocky young lady's man whose written resolution of Goldbach's Conjecture, "the most difficult problem in the history of mathematics", was stolen from his rooms shortly before it was due to be published. Middle-aged 'Hilbert' (Lluís Homar) is a rakish if depressed lover of puzzles. Practical Pascal (Santi Millán) is an engineer and inventor with a barely concealed drinking problem. Beautiful Oliva (Elena Ballesteros) gives little away.