But suddenly they started forward in a rigid, fixed stare, and his lips parted in amazement.

At the same instant Lestrade gave a yell of terror and threw himself face downward upon the ground.
I sprang to my feet, my inert hand grasping my pistol, my mind paralyzed by the dreadful shape which had sprung out upon us from the shadows of the fog.

A hound it was, an enormous coal-black hound, but not such a hound as mortal eyes have ever seen.

Fire burst from its open mouth, its eyes glowed with a smouldering glare, its muzzle and hackles and dewlap were outlined in flickering flame.

Never in the delirious dream of a disordered brain could anything more savage, more appalling, more hellish be conceived than that dark form and savage face which broke upon us out of the wall of fog.
With long bounds the huge black creature was leaping down the track, following hard upon the footsteps of our friend.