A diamond advocate is attempting to steal a collection of diamonds, yet troubles arise when he realizes that he is not the only one after the diamonds.
Sherlock Holmes investigates strange and tragic happenings in a village that appear linked to a man who seems to be like a vampire.
Holmes investigates a killing which has all the hallmarks of the worst kind of Ruritanian vampire. He is sceptical (to say the least) about the possibility that the undead are up to their mischief just a short train journey from his rooms in Baker Street. If a local resident really found his South American wife sucking blood from their young son, what might it signify?