The Adventure of the Creeping Man by Arthur Conan Doyle. Short summary

5 seconds

An elderly professor has strange seizures during which he acts like an animal. Holmes discovers that it is a side effect of a rejuvenating serum.

1 minute

Holmes is approached by Mr. Bennett, Professor Presbury’s assistant and his daughter’s fiancé. The elderly scientist has proposed to his colleague’s young daughter. But the girl was embarrassed by his age.

Presbury leaves for Prague. After the trip, he regularly receives secret letters from London. After receiving them, the professor behaves strangely — he walks on all fours, climbs up a drainpipe, and growls at his loved ones.

Holmes suspects that in Prague the professor was advised to take some kind of a drug, which he receives from London. After taking it the strange attacks happen.

When Presbury once again receives a letter, Holmes and Watson go to his house. They see the professor acting like an animal and being attacked by his own dog. The professor is rescued. Holmes discovers that the old man was allegedly taking a rejuvenating serum.