Mr. Alden had watched for five nights when he knew the pressman to be at home. On four of them Sheard's light had been extinguished before midnight. To-night, the fifth, it had remained burning, and long vigilance had been rewarded.
A car had drawn up at some distance from the house, and its occupant had proceeded forward on foot. He had been admitted so rapidly that Alden had been unable to ascertain by whom. The car, too, had been driven off immediately. He had had no chance of taking the number; but was astute enough to know that in any event it would have availed him little, since, if the car were Bablon's the number would almost certainly be a false one.
For once in a way, Mr. Alden became excited. Whom could so late a visitor be, save one who wished to keep secret his visit? In attaching his eavesdropper he had clumsily raised his head above the level of the window-ledge, but he had hoped that this gross error of strategy had passed unnoticed. For a time he had failed to pick up the conversation until his ear became attuned to the subdued tone in which it was conducted. Thus, he had lost the key to its purport and had had to improvise one.
But, even so, words had passed which had amply confirmed his suspicions; so much so that, whilst he listened, all but breathlessly, he was devising a scheme for capturing Sheard's visitor, single-handed, as he left the house. Furthermore, he was devising a way out of the difficulty in the event of the captive proving to be another than Séverac Bablon.
The latter part of the duologue had puzzled him badly. The visitor seemed to have ceased talking altogether, and Sheard's remarks had in some inexplicable way drifted into quite a different channel. They appeared to appertain to what had preceded them but remotely. The relation seemed forced.
Still the visitor said nothing. Sheard continued to talk, and in upon the mind of the detective shone a light of inspiration.
He detached the cunning little instrument, crawled across the lawn and slunk out at the gate. Then he ran around to the rear of the house. A narrow lane there was, and into its black mouth he plunged without hesitation.
The gate of the tradesmen's entrance was unbolted.
Alden was perfectly familiar with the nightly customs of the Sheard establishment, and knew this to be irregular. He tilted his hat back and scratched his head reflectively.
Then, from somewhere down the road, on the other side of the house, came the sound of a curious whistle, an eerie minor whistle.