“Let me see,” said the invisible man, and advanced, arm extended, to the door.

And then things happened very swiftly. Kemp hesitated for a second and then moved to intercept him. The invisible man started and stood still. “Traitor!” cried the voice, and suddenly the dressing gown opened, and sitting down the unseen began to disrobe. Kemp made three swift steps to the door, and forthwith the invisible man⁠—his legs had vanished⁠—sprang to his feet with a shout. Kemp flung the door open.

As it opened, there came a sound of hurrying feet downstairs and voices.

With a quick movement Kemp thrust the invisible man back, sprang aside, and slammed the door. The key was outside and ready. In another moment Griffin would have been alone in the belvedere study, a prisoner. Save for one little thing. The key had been slipped in hastily that morning. As Kemp slammed the door it fell noisily upon the carpet.