The Doves of Vengeancet (The Adventures of the Elderly Sherlock Holmes, Episode 13)

A kidnapped cat, an eccentric cat owner who is a university friend of Holmes, a missing pigeon and the pigeon owner, who has endured more suffering in his life than many others could bear. These are the facts of a new case that doesn't appear particularly spectacular at first glance. This changes dramatically when the first corpse is found with its throat slashed. And unfortunately, this dead person won't be the last...