Four mathematicians who do not know each other are invited by a mysterious host on the pretext of resolving a great enigma. The room in which they find themselves turns out to be a shrinking room that will crush them if they do not discover in time what connects them all and why someone might wish to murder them.
| Writing | Luis Piedrahita | Screenplay |
| Writing | Rodrigo Sopeña | Screenplay |
| Production | Laura Cepeda | Casting |
| Art | David Fernández | Art Direction |
| Directing | Rodrigo Sopeña | Director |
| Editing | Jorge Macaya | Editor |
| Camera | Migue Amoedo | Director of Photography |
| Production | Adolfo Blanco | Producer |
| Production | José María Irisarri | Executive Producer |
| Directing | Luis Piedrahita | Director |
| Production | César Benítez | Producer |
| Sound | Federico Jusid | Original Music Composer |
| Sound | Ale Martí | Music |
| Costume & Make-Up | Santos Sánchez | Costume Design |
| Costume & Make-Up | Eva Fontenla | Makeup Artist |
| Sound | Oriol Tarragó | Sound Designer |
| Sound | David Calleja | Sound Re-Recording Mixer |
| Sound | Licio Marcos de Oliveira | Sound Designer |
