The casebook is composed of three novellas:
The Case of the Blind Medium
Count Benjamin Farrens does the best to remain an eccentric member of English nobility while also investigating supposedly supernatural occurrences. When a simple séance turns into a murder case, he does his best to protect an innocent, blind boy and to help find the murderer.
The Case of the Blood Ruby
Count Benjamin Farrens is just about to settle down a little more, now that he has a foster son to take care of, but his plans are derailed when a charming young woman from Japan arrives and proclaims herself his fiancé. Nevertheless, her help is invaluable when a cursed gem, aptly called the Blood Ruby, is stolen and a man is murdered during the theft. Blood and death follow the gem, that much is clear soon.
The Case of the Cornwall Vampire
When Inspector Irenicus Wilsborough complains about a case in Cornwall, where a tourist was bitten by a fellow human, Count Benjamin Farrens packs up his fiancé, his foster son, his valet, and his new coachman and takes a vacation in Cornwall with the aim of finding the madman who goes around biting people. It is a case more dangerous than anything he's tackled before.