Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
The series aired on Secondo Programma from 25 October to 29 November 1968 and is formed by six episodes: the first three episodes adapt The Valley of Fear while the last three episodes adapt The Hound of the Baskervilles. Each episode is about one hour long.