He thought over this problem until night fell, and retired to bed with it still unanswered.

But the solution flashed into his mind at breakfast next morning, suddenly, like light in a dark place.  He was amazed that he had not seen it before.  “If it is that ...” he whispered.  But he knew it was that; knew also, that it meant the worst.  He got up from the table, then forced himself to sit down again and eat.  An untouched breakfast tray might quicken the suspicions in the mind of that most treacherous woman downstairs, might hasten her hand.  But why had she delayed so long?

He passed the morning between his chair and the window, watching, and listening for footsteps.  He saw Mrs. Brierly leave the house early, and wondered if she would return with the police.  Another reflection came to his mind.  Charles had some inkling, and had fled in time.  Perhaps that was just as well, if he got out of England.  For himself there was no such retreat, nor did he wish it.  He would have to face things out, if they had to be faced, and he did not yet despair of saving the situation, so far as it affected himself.  What did that diabolical female know, really?  He had a momentary vision of her stealing about the house, prying, watching, listening.  He sank into a motionless brooding reverie.

The day passed its meridian, but he still sat there in solitude with his anxious thoughts.  As the afternoon declined his hopes rose.  Could it be that he was mistaken, that his fears were imaginary?  Perhaps, after all—­

At that sharp ring of the doorbell downstairs he walked noiselessly to the window, and shrank back with the startled look of a man who has had his first glimpse of the bared teeth of the law.  He stood still, listening intently.  He heard the door opened, a sharp question, then the sound of ascending footsteps.  When the knock came at his own door he was in complete command of himself as he went to open it.  He was well aware of the ordeal before him, but he did not show it.  There was nothing but ironical self-possession in the glance which took in the figures of Detective Barrant and Inspector Dawfield, revealed on the threshold of the opening door.

Barrant lost no time in coming to the point.  “I want to see your son,” he said, entering and glancing quickly round the apartment.

“I am afraid that is impossible.”

“Why?”

“He is not here.”

“Where is he?”

“I think he has gone to London.”

Barrant was plainly taken aback at this unexpected piece of news.  “When did he go?” he demanded.

“Yesterday evening.”

Barrant cast a look at Dawfield, which said plainly:  “He’s had word of this and bolted.”  His glance returned to Austin.  “Can you tell me where he is staying in London?”

“I have not the least idea,” returned Austin negligently.

“Does he not live with you?”

“As a rule—­yes.”