Nothing clears up a case so much as stating it to another person.

Of all ruins, that of a noble mind is the most deplorable.

Far away on the path we saw Sir Henry looking back, his face white in the moonlight, his hands raised in horror, glaring helplessly at the frightful thing which was hunting him down. But that cry of pain from the hound had blown all our fears to the winds. If he was vulnerable he was mortal, and if we could wound him we could kill him. Never have I seen a man run as Holmes ran that night.

...it was a huge creature, luminous, ghastly, and spectral. I have cross-examined these men, one of them a hard-headed countryman, one a farrier, and one a moorland farmer, who all tell the same story of this dreadful apparition, exactly corresponding to the hell-hound of the legend. I assure you that there is a reign of terror in the district, and that it is a hardy man who will cross the moor at night.

if i could be assured of your destruction, i would in the interest of the public, cheerfully accept my death.

He is not a bad fellow, though an absolute imbecile in his profession. He has one positive virtue. He is as brave as a bulldog and as tenacious as a lobster if he gets his claws upon anyone.

There are always some lunatics about. It would be a dull world without them.