HANDCUFFS Dale had failed with the Doctor.

When Lizzie's screams once more had called the startled household to the living-room, she knew she had failed.

She followed in mechanically, watched an irritated Anderson send the Pride of Kerry to bed and threaten to lock her up, and listened vaguely to the conversation between her aunt and the detective that followed it, without more than casual interest.
Nevertheless, that conversation was to have vital results later on.
"Your point about that thumbprint on the stair rail is very interesting," Anderson said with a certain respect.

"But just what does it prove ?" "It points down," said Miss Cornelia, still glowing with the memory of the whistle of surprise the detective had given when she had shown him the strange thumbprint on the rail of the alcove stairs.
"It does," he admitted.

"But what then ?" Miss Cornelia tried to put her case as clearly and tersely as possible.
"It shows that somebody stood there for some time, listening to my niece and Richard Fleming in this room below," she said.
"All right--I'll grant that to save argument," retorted the detective.
"But the moment that shot was fired the lights came on.