In order to show his good professional style, the new prison guard Juan (Alberto Ammann) went to prison one day in advance to experience the work. On this day, the prisoner leader "Evil Mother" injured the prison guard and led the prisoners to riot, and the prison fell into chaos... Juan was abandoned in cell 211 by his companions because of his injury. In order to avoid being taken hostage by the prisoners, he had to disguise himself as a criminal, gain the trust of the evil mother, and try to find a chance to escape. The prisoners threatened the officials to agree to their negotiation conditions with three "ETA" terrorists with sentences of more than 100 years in prison. Because the government had an agreement with ETA, the prison and the special operations team were afraid to attack, which led to a stalemate. On the other hand, the prison riot caused a chain reaction after being reported by the media. Family members came to the prison to inquire about the news, but were beaten by the prison guards. Juan's pregnant wife was unfortunately injured, which made Juan, who wanted to ensure his own escape and assist the prison authorities in calming down the situation, do something crazy... This film swept eight major awards including the 2009 Spanish Goya Awards for Best Film, Director, and Actor.