He woke and in the most business-like way went downstairs into the basement, where from a cupboard he took a large screw-driver, walked to the chests, cut the ropes, and carefully examined the seals attached to the lesser cords before disturbing them. Then, apparently satisfied, he cut these in turn, and began to take out the screws from the lid of the first chest.

He had reached the last screw when he suddenly stopped short and stood listening. The next minute he had walked to the end of the passage, to stand listening again, till apparently satisfied, he went into a dark corner and pulled at a knob as if ringing a bell. Then he went sharply back to the chests, laid down the screw-driver, and hurried up the stairs to the dining-room with all the activity of a man of forty.

Here he went to a book-case and took down an ancient-looking massive tome, laid it upon the table, lifted the cover, and showed that it was only an imitation book, the cover proving to be the lid of a box in which lay a mahogany case, from which he drew out a small revolver, and after examining its six chambers to see if they were loaded, he carefully concealed it in the breast of the vest he wore beneath the old dressing-gown.

Then the spectacles were resumed, and the slow, stooping, aged aspect came over him, as he went into the hall, threw off his dressing-gown and took an old-fashioned coat from a peg, donned it, and then completed his old-world aspect with a quaint broad-brimmed hat.

He looked the most peaceable of elderly gentlemen as he took a baggy umbrella from the stand, went out, closed the door after him, walked slowly along by the area railings for a few steps, and then turned up the steps to the Clareboroughs’ door, passing into the hall so quickly that it seemed as if the door was opened from the inside, though anyone who had watched would have seen that there was a very quick, clever application of a latch-key.

His movements now were slow, deliberate and silent. He laid down umbrella and hat upon a table, and, apparently quite at home, went from room to room on the ground floor before ascending to the drawing-rooms; but finding no one, he went a floor higher and then descended to the hall, where from the top of the stairs he stood listening to the hammering going on below.

For some time he seemed undecided how to act, but at last he was in the act of descending, when steps below made him retreat, and he stepped back, listening, and hearing Roach go into the pantry. The next minute the man began to ascend, and as actively as a cat, and with as silent a step, the professor ran to the foot of the grand staircase and bounded up to the drawing-room floor, ensconced himself behind a heavy curtain which draped one of the doors, and made out that whoever it was reached the hall and went into dining-room, library, study, lobby and morning-room, before he went back to the stairs and descended once more to the basement.

The professor was after him directly, and at the head of the stairs in time to hear Roach come out of the pantry again, and the chink of a glass against a bottle.

He descended the gloomy stairs by slow degrees, listening the while to the work going on, and hearing the sound of tools, the whisperings, and after a long period of waiting and another forced retreat when Roach went again to the pantry to make sure the housekeeper was safe, he finally stood thinking.

“Someone who knows the place well,” he said to himself. “Quite at home. Where can the old woman be? They can’t have killed her.”