“The blow that killed Maddy was powerfully dealt,” said Tom; “and I can’t help thinking it was some tramp or professional burglar who was clever enough to elude Harris’s fastenings. Or some window may have been overlooked that night. At any rate, we have no more plausible theory.”

“We have not,” said Mr. Fairbanks; “but I for one am not content to let the matter rest here. I should like to suggest that we call in some celebrated detective, whose experience and skill would discover what is beyond the powers of Mr. Fessenden and myself.”

Rob felt flattered that Mr. Fairbanks classed him with himself, and felt anxious too that the suggestion of employing a more skilful detective should be carried out.