In these questions, the first and last sentences of the passage are numbered 1 and 6. The rest of the passage is split into four parts and named P, Q, R, and S. These four parts are not given in their proper order. Read the sentences carefully and find out the correct sequence of the sentences. 

S1: The Hound of Baskervilles was feared by the people of the area.

P : Some people spoke of seeing a huge, shadowy form of a Hound at midnight on the moor.

Q : But they spoke of it in tones of horror.

R : Nobody had actually seen the hound.

S : This shadowy form did not reveal any details about the animal.

S6: The Hound of Baskervilles remains an unsolved mystery.