"Good!" cried Raffles. "I was only afraid you might be on his tracks once more!"

Mackenzie shook his head with a dry smile, and wished us good evening as an invisible window was thrown up, and a whistle blown softly through the fog.

"We must see this out," whispered Raffles. "Nothing more natural than a little curiosity on our part. After him, quick!"

And we followed the detective into another entrance on the same side as that from which we had emerged, the left-hand side on one's way to Piccadilly; quite openly we followed him, and at the foot of the stairs met one of the porters of the place. Raffles asked him what was wrong.

"Nothing, sir," said the fellow glibly.

"Rot!" said Raffles. "That was Mackenzie, the detective. I've just been speaking to him. What's he here for? Come on, my good fellow; we won't give you away, if you've instructions not to tell."

The man looked quaintly wistful, the temptation of an audience hot upon him; a door shut upstairs, and he fell.

"It's like this," he whispered. "This afternoon a gen'leman comes arfter rooms, and I sent him to the orfice; one of the clurks, 'e goes round with 'im an' shows 'im the empties, an' the gen'leman's partic'ly struck on the set the coppers is up in now. So he sends the clurk to fetch the manager, as there was one or two things he wished to speak about; an' when they come back, blowed if the gent isn't gone! Beg yer pardon, sir, but he's clean disappeared off the face o' the premises!" And the porter looked at us with shining eyes.

"Well?" said Raffles.

"Well, sir, they looked about, an' looked about, an' at larst they give him up for a bad job; thought he'd changed his mind an' didn't want to tip the clurk; so they shut up the place an' come away. An' that's all till about 'alf an hour ago, when I takes the manager his extry-speshul Star; in about ten minutes he comes running out with a note, an' sends me with it to Scotland Yard in a hansom. An' that's all I know, sir—straight. The coppers is up there now, and the tec, and the manager, and they think their gent is about the place somewhere still. Least, I reckon that's their idea; but who he is, or what they want him for, I dunno."