A former fortress nestled in the mountains now houses the freeEssence, a psychiatric clinic where the human mind is studied.
Edgar, head of the clinic, is away at conferences when a man suffering from dissociative identity disorder shows up. The doctors immediately focus on an anomaly: subjects with this condition, in an attempt to escape from a mean and intolerable existence, identify themselves as notorious characters. But their patient claims to be a certain Dr. Julius Vock, a complete stranger.
Plus, the disorder proves to be particularly resistant to therapy.

The case becomes more complicated when another man with the same pathology arrives at the clinic, claiming to be the same unknown character.
New investigations start and, with the help of a police officer friend, they try to recover information about the two patients and the mysterious Julius Vock. Who is he? Is he invented or he really existed? What was the relationship between the three of them?
Edgar can no longer delegate, he must return to the clinic: a case like this could lead to medical and scientifical discoveries of absolute relevance, possibly changing his life forever.