Six total strangers awaken one day to find themselves alone in a cubical maze of interlocking metal cubes. The diverse group consist of Leaven (Nicole de Boer), Holloway (Nicky Guadagni), Worth (David Hewlitt), Kazan (Andrew Miller), Alderson (Julian Richings), Rennes (WWayne Robson) and Quentin (Maurice Dean Wint).
Leaven is a privileged young woman whose hidden mathematical talent plays an important role in the groups attempt to escape their hell. Holloway is an outspoken, opinionated socially conscious free-clinic doctor who has dozens of eccentric conspiracy theories. Worth is blunt and cynical and trapped in his own personal hell but who has an inside knowledge of the CUBE. Kazan is a mentally challenged man who is largely indifferent about escaping this hell and is a large burden to his fellow prisoners. Rennes is the mysterious but methodical one when broaching the science of their escape. Quentin is the police detective who blames everyone but himself for their current entrapment.
Once they meet each other, the group must work together using their individual skills and talents to survive the deadly traps which guard the colored metal cubic rooms.
Using Leaven's mathematical skills, they press forward, upward, and downward through the hatches of the cube's to try and find the outer shell and their freedom.