The book recounts the daily life of an employee of the Centre d'Aide aux Handicapés Mentaux, the CAHM. A mentally handicapped man himself, he is relegated to an insignificant position as the Centre's archive clerk. A fierce loner, his only companions are his old cat and the psychiatrist, an inveterate drinker and a bit of a crackpot at the CAHM. On his wedding night, his mother is found dead, while his future wife has disappeared. He is suspected of patricide, and has a few problems with the police and the neighbours. The rest of the story is a succession of zany chronicles of the CAHM, the neighbourhood and the estate in general, in which our hero finds himself involved, in spite of himself, in funny situations that put him to the test.