"You, young fellow," continued the inspector, addressing the chauffeur, "may know something of the ins and outs of this place. Do you know if there's a back door to the main building?"
"There is—yes—down behind that barn."
"Then pull out a big spanner, or anything handy, and go round there. When you reach the door, whistle. Stop there unless you hear my whistle inside or till I come through and join you. If he's not in the main building we can start on the outhouses. But his escape is cut off all the time by Mr. Belford—see?"
"Quite right, inspector! Quite right!" cried Mr. Belford. "Go ahead! I will get to the car! Go ahead!"
Off ran the agile politician to his appointed post; and the chauffeur, armed with a heavy spanner, disappeared in the shadow of the barn. Sheffield, taking from his breast-pocket an electric torch, strode up to the doorless entrance of the abandoned farm, and waited.
CHAPTER XXVI
GRIMSDYKE
Not a sound disturbed the silence of the deserted place, save when the slight breeze sighed through the trees of the adjoining coppice, and swayed some invisible shutter which creaked upon its rusty hinges.
An owl hooted, and the detective was on the alert in a moment. It was a well-known signal. Was the owl a feathered one or a human mimic?