“Well, to tell the story in detail,” said his step-son, “the way it happened is this.  Aunt Selina had Mr. Hale and Mr. Clancy and Mrs. Herne to their usual game of whist.  Clancy, as it appears from the report of what the new parlor-maid overheard, quarrelled with Hale and Mrs. Herne.  They left before ten o’clock.  At all events, when she entered the room in answer to my aunt’s summons, she found only Mr. Clancy, and aunt was scolding him for having provoked Mrs. Herne by contradicting her.  Apparently Mrs. Herne had gone away under the wing of Hale.  Then aunt sent Clancy away at ten o’clock.  The parlor-maid returned to the kitchen and there had supper.  She heard the bell ring at eleven, and found aunt dead in the sitting-room, stabbed to the heart.”

“Heard the bell ring?” echoed Juliet.  “But how could aunt ring if she had been killed?”

“She might have rung as she was dying,” said Basil, after a pause.  “It seems she was seated near the button of the bell and could have touched it without rising.  She might have rung with a last effort, and then have died before the parlor-maid could get to the room.”

“Or else,” said Mr. Octagon, anxious to prove his perspicuity, “the assassin may have stabbed her and then have touched the bell.”

“What!” cried his step-son derisively, “to summon a witness.  I don’t think the assassin would be such a fool.  However, that’s all that can be discovered.  Aunt Selina is dead, and no one knows who killed her.”

“Was the house locked up?” “The front door was closed, and the windows were bolted and barred.  Besides, a policeman was walking down Crooked Lane a few minutes before eleven, and would have seen anyone leaving the house.  He reported that all was quiet.”

“Then the assassin might have rung the bell at eleven,” said Peter.

“Certainly not, for he could never have escaped immediately afterwards, without the policeman seeing him.”

“He might have got out by the back,” suggested Juliet.

“My dear girl, what are you thinking of.  That wall round Lord Caranby’s mansion blocks any exit at the back.  Anyone leaving the house must go up the lane or through that part at the bottom.  The policeman was near there shortly before eleven and saw no one leaving the house.”

“But, look here,” said Mr. Octagon, who had been ruminating; “if, as the doctor says, death was instantaneous, how could your aunt have rung the bell?”

“Yes,” added Juliet.  “And even had death not taken place at once, it could not have been more than a few minutes before eleven when the blow was struck.  Aunt might have had strength to crawl to the bell and touch it, but the assassin could not have escaped from the house, seeing—­as you say—­the policeman was on guard.”

“Aunt died instantaneously,” insisted Basil.

“Then she could not have sounded the bell,” said Juliet triumphantly.