Episode 5 of the The Good Detective's Diary series
Professor Kamil Puiskailer is sentenced to thirteen years for the murder of his wife. He's interned in cell number 17. With three killers. The prison governor decides to use his mathematical knowledge to prepare his own son for the matriculation exam. Everything turns out well and for a reward he transfers the professor from the mangle room to the administration.
The professor begins to write a memoir from a long time ago. Diary in red boards. Coincidentally, Detective Krauz gets hold of his notes. He understands from the text of the diary that there is something not quite right about the professor's conviction. He asks his colleague and friend Chosé for help. The search for the truth on your own begins.