In an unusual twist for Fenn, much of the action in this novel takes place on the lower floors of a doctor's house in nineteenth century London. The doctor having been for some years been obsessed with an idea that he could make an elixir of eternal life, has started to neglect his patients, so much so that very few new patients remain. Without much money in the house times are hard, when the most amusing character in the book, Bob the "boots" boy, makes a most remarkable discovery...
"Key in," he said gruffly, "locked inside. Who's likely to be here?"
"My father. He always sits in the consulting-room beyond at night-- studying."
Another short nod, and the constable rapped loudly. No response.
He rapped again, with the same result. Then he drew a long breath, and the man showed that he possessed feeling as well as decision.
"I don't want to alarm you, Miss, but I ought to force open this door."
"But you do alarm me, man. Yes, you are right. No! let me come."
She rapped smartly on the door.
"Father! Father! Are you here?"
Still no reply; and she drew back, looking wildly in the constable's eyes, while her hands seemed as if drawn together to clasp each other and cheek the nervous trembling and be of mutual support.
"Yes," she said, "force it open. Stop! break one of the panes."
The constable leaned his shoulder against the pane nearest the lock, and there was a sharp crackling noise, the splintered glass being caug