Here's the room, sir." He paused before the door of a room which stood halfway down a long corridor in the centre of the hotel, and on its panels he knocked gently.
"Every room's filled on this floor, sir," he remarked.

"I hope your friend's a light sleeper, for there's some of 'em'll have words to say if they're roused at four o'clock in the morning." "He's a very light sleeper as a rule," replied Allerdyke.

He stood listening for the sound of some movement in the room: "Knock again," he said, when a minute had passed without response on the part of the occupant.

"Make it a bit louder." The night-porter, with evident unwillingness, repeated his summons, this time loud enough to wake any ordinary sound sleeper.

But no sound came from within the room, and after a third and much louder thumping at the door, Allerdyke grew impatient and suspicious.
"This is queer!" he growled.