not to abort the experiment. 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. Dora meanwhile returns to Tarek's apartment and discovers his participation contract for the experiment. She surprises him by showing up for a visit day. 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. Berus intercepts Bosch, however, and tells Dora that everything is all right and refuses to let Tarek see Dora. The situation becomes critical and more violence is involved. The prisoners are being abused and their self-esteem is drastically decreased by the guards' power. 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. Later he suffocates to death due to his bloody nose drying up while gagged. Bosch is beaten by the other guards for his "betrayal" and is put into confinement. Lars, a member of Thon's team, notices this and attempts to contact Professor Thon, who is attending a conference. The guards, who are aware that the professor cannot be reached by phone, are convinced by Berus that the entire situation is a test put up by Thon's team, in order to make the guards handle an exceptional situation. They take over control of the facility and capture Lars, Dr. Grimm and the other scientists, who are put into confinement as well, and gradually start their own prison in which they engage in brutally sadistic games with total control. Dora comes to the facility a second time to speak to Tarek and is lured into a room by Berus, where he locks her up. Dr. Grimm is handcuffed and gagged with duct tape while the guard Eckert attempts to rape her. He is stopped by Tarek, who escaped from solitary confinement through the use of a screwdriver that he found inside the "black box". Tarek knocks down Eckert and frees Lars, Bosch, Steinhoff, Dr. Grimm and the other prisoners. They manage to escape by removing the wall paneling of one of the cells with the screwdriver. Meanwhile, Professor Thon hears Lars' desperate message in his voicemail and leaves