Detective Devrinne was on holidays in France. He was from Quebec and he was related with a remote cousin who invited the detective to visit him. Mike Devrinne was tired of inquiries in Boston, yet his cousin insisted. Several homeless people disappeared, and some of them were found with hid surgical marks. One of them escape with electric shock traces and a tentative of lobotomy. He looks not like the other homeless people, he has a tatoo on a shoulder, may be from an american university. A strange doctor seems to be involved and Devrinne found photographies of the 1950ties where he is near the famous Professor Hamburger, father of a music composer and inventor of the first artificial kidney. Devrinne forgot his holidays and helped a sympathetic doctor and his friend to find the disappeared people.