The Case of the Vampire's Curse - The New Adventures of Sherlock Holmes, Episode 4 (Unabridged)

Baron Collingwood's eldest son and title heir dies from a mysterious illness. Now that the second eldest son is also in bad condition, it seems that a curse has befallen the family. Neither doctors nor police are able to find the cause. Confronted with a riddle the Baron hires Holmes and Watson to solve the mystery before it is tool late.