And these finger-prints were those of a gentleman's hands.

Do you want me to go on, Lord Heyton ?" Heyton could not speak; his tongue seemed to cleave to the roof of his mouth; he felt as if his spine were giving way, as if all his strength of mind and body were ebbing from him.
"It's--it's ridiculous!" he stammered.
"No, my lord, it's quite simple, quite elementary.

There were the finger-prints, on the safe, on the walls, on the poker.

I could read them quite easily with a magnifying glass; and they never lie.

'Pon my word, Lord Heyton!" he broke off musingly, his mouth twisting into a smile, "I'm inclined to think they're the only things in this world one can rely on.