Books like He Who Whispers
John Dickson Carr
He Who Whispers is 206 pages, about 3 hours 47 minutes at 250 words a minute.
12 books to read next
How long each takes
Whose Body? 3.9 h 
Peril at End House 4.1 h 
Dead Cert 4.5 h 
Endless Night 4.4 h 
Odds Against 5.1 h 
Elephants Can Remember 4.4 h 
The Seven Dials Mystery 4.6 h 
Third Girl 4.7 h 
The Big Four 4.1 h 
The Valley of Fear 3.8 h 
The Clocks 4.7 h 
Mrs. McGinty's Dead 4.3 h Bar height shows length. Estimated at 250 words a minute.