Der Handymörder.

Former GDR secret service agent Wolfgang Dreher is sentenced to life imprisonment. While still in the courtroom, he threatens to wake up his sleepers if the sentence is not overturned. The assignment: the Federal Prosecutor General. Nicola Helling, an agent at the Federal Criminal Police Office, tries in vain to prevent the assassination attempt. But Dreher is still not free. His next assignment: an assassination attempt on the Federal Chancellor. Nicola Helling heads the SOKO, which is searching for the sleeper agent - who is apparently among the ranks. When Dreher dies in prison, the only link to the killer is lost...