"He may have escaped by the window," suggested Bob.
Rivers shook his head. "He could not do so without breaking his limbs. This floor is some distance from the ground, and a dead straight wall stretches down the back of the house."
"There may be other panels in the walls of his room opening in other directions."
"That is more likely. It is stupid to wait here and do nothing. I have picked a lock before to-night. Here goes."
Down he plumped on his knees, and set to work with his own knife and ours which we handed him. One or another of us held a candle to the keyhole while he worked. It was a long job and a tough job, and he was at it for thirty or forty minutes, but he managed it at last.
"Be prepared for a rush," he said, in a tone of warning, as he slowly pushed the door open.
No such experience awaited us. The door was wide open, and we stood together on the threshold.
"He has left the candle alight, at all events," said Rivers. "Follow me, and look out."
We entered the room close upon each other's heels.
Leaning back in an armchair by the table was Mr. Nisbet. His eyes were closed, and we were face to face with the murderer. His features were perfectly calm and composed.
"How can he sleep so peacefully at such a moment as this?" whispered Bob.
"Yes," said Rivers, stepping forward, "he sleeps peacefully."
Dr. Cooper also stepped forward, and put his ear to Mr. Nisbet's mouth, and his hand to his heart.
Rivers lifted from the carpet an empty vial which had fallen from the dead man's hand, and held it up to the doctor with a questioning look. Dr. Cooper nodded.
Beatrice was taken back to England, and under medical care recovered her memory. But she recollects very little of the years she passed in peril of her life. The chief part of her fortune was saved, and she and Ronald are married. Barbara is in their service. The poor child suffered much when the truth was revealed to her, but time healed her sorrow, and she has a happy home.
Dr. Cooper disappeared from London, and none of us knew, or cared to know, what became of him. Ronald provided for Mme. Bernstein.
My good wife and I live in our old home. We never intend to move. Nothing in the world could tempt Maria to enter an empty house. Between ourselves and Mr. and Mrs. Elsdale exists a firm friendship, and we, seldom without Bob, are frequently together; but we never refer to the strange incidents which have ended so happily.