Professor Jasper Tempest, a genius Cambridge University criminologist with OCD and an overbearing mother, advises the police. British version of the Belgian crime drama of the same name.
The professor's new pet fish is found dead by the housekeeper. She replaces it with another ( without telling the prof) & ithe new fish tells the professor his name is Walter. Evidently the Professor overfed the 1st one. :-(
Occasional flashback scenes, worst one is in S1E6. It's strongly implied that the main character's father was highly abusive before his death before the events of the first episode.