"Then go and knock!"
The boy obeyed with alacrity. He rapped loudly on the door, not noticing or not caring that the visitor was standing directly behind him. The shutter was lowered and a grizzled, bearded face showed for a moment through the opening.
Bristol leant over the boy and pushed a card through into the hand of the man beyond. On this occasion it did not bear the legend "John Henry Smith," but the following—
CHIEF INSPECTOR BRISTOL C.I.D. NEW SCOTLAND YARD
"Good afternoon, Mr. Knowlson," said the detective dryly. "I want to come in!"
There followed a moment of silence, from which Bristol divined that he had blundered upon some mystery, possibly upon a big case; then a key was turned in the lock and the door thrown open.
"Come right in, Inspector," invited a strident voice. "Carter, you can go home."
Bristol entered warily, but not warily enough. For as the door was banged upon his entrance he faced around only in time to find himself looking down the barrel of a Colt automatic.
With his back to the door which contained the wicket, now reclosed, stood the man with the bearded face. The revolver was held in his left hand; his right arm terminated in a bandaged stump. But without that his steel-gray eyes would have betrayed him to the detective.
"Good God!" whispered Bristol. "It's Earl Dexter!"