In the experiment, the prisoners lose their civil rights and have to obey arbitrary rules, such as the obligation to completely finish their meals.

It becomes clear that limits are not only being reached, but being surpassed when the guards kidnap Tarek from his cell late in the night, order him to strip fully naked, shave his head bald and urinate on him.

Dr. Grimm suggests putting an end to the alarming situation, but Professor Thon refuses to stop the experiment until the violence has reached a maximum.

Tarek, who was forced to clean the toilet with his own clothes, pleads to the friendly guard Walther Bosch to secretly bring her a message.

Most of the violence is directed against Tarek and he is locked up in solitary confinement inside a "black box" resembling a safe.

Schütte, protesting this, is beaten severely, bound and gagged with duct tape and forced to sit on a chair.

He is stopped by Tarek, who escaped from solitary confinement through the use of a screwdriver that he found inside the "black box".

Professor Thon reaches the facility and demands an explanation from Eckert, who accidentally injures him with a pistol.

The film ends with a news break, confirming two deaths (Schütte and Eckert) and three severely injured (Thon, Berus, and Bosch).

In a positive review, Roger Ebert stated that he was impressed by the film's effectiveness, even though he viewed its outcome as predetermined.

[3] According to Karen Durbin of the New York Times, the movie can be seen as an allegory for the rise of authoritarian governments such as the Nazi regime.

[2] An American remake released in 2010 was directed by Paul Scheuring and stars Adrien Brody, Forest Whitaker, Maggie Grace, and Cam Gigandet.