Alois Meininger (Martin Leutgeb), a convicted murderer, is released from preventive detention after more than 30 years, commits another murder and goes into hiding. No one can provide any clues as to where he might be staying - the last hope lies with his former therapist Norbert Prinz (Peter Franke), who is now suffering from dementia. But how can you interview someone with dementia? In collaboration with the renownedNeuropsychologist Prof. Vonderheiden (André Jung) starts a criminological pilot project: The former practice room is to be resurrected as a backdrop and the demented test person is to be led inside. The inspectors hope to be able to elicit valuable information from him. But in the course of the experiment, Batic (Miroslav Nemec) and Leitmayr (Udo Wachtveitl) reveal deeper abysses than initially assumed.