Now that the reader has learned who the culprit is, how is the suspense built up? Chapter 12

Right as Holmes admits that Stapleton's plan must be murder, the men hear the hound's cries out on the moor. They rush out towards the direction of the sound, Holmes lamenting that Stapleton has struck before Holmes could ensnare him. As they arrive near the source of the sound, they hear a human moan and then see a body fall from a great height. They recognize Sir Henry's clothes on the figure, and realize their charge is dead.

They both blame themselves - Watson for leaving Sir Henry alone, Holmes for having delayed his action - and then climb onto the rocks to try and spot the hound. Instead, they spot the Stapleton house and briefly plan how to ensnare the culprit. Suddenly, Holmes realizes that the corpse has a beard - it is not Sir Henry, but Selden! Watson realizes that Barrymore must have given Sir Henry's extra clothes to the man.

They then wonder two things: why Selden would have been so frightened of the sound, and why Stapleton would have thought to release the hound on this night.

Before they can answer either, Selden strolls up, surprised to see them. His surprise is even greater, though, to discover the convict's body. He claims he heard the sound as well, and then quickly identifies Holmes. The men talk vaguely as Holmes sizes him up, and then decide they must leave the body with something over its face until the next day.