“The back stairs?” Bernard suggested mildly.
Landis stared at him.
“Might as well stop trying to steal a march on you!” he grumbled. With a laugh of good fellowship he retraced his steps, returned presently with Harley, accompanied the chauffeur to the garage and came back with a torch. He sent Harley back to the library. He and Bernard passed through the billiard-room into the sunken garden which Harley had watered that evening.
The house enclosed the garden on two sides, the billiard-room behind them and the wing to their right. It was enclosed on the other sides by a high brick wall. This was pierced by an arched opening opposite the billiard-room door. A rambling path joined the two.
Landis followed the path, keeping his torch low. In a moment he found a muddy patch where the path dipped slightly and near the edge of it the imprint of a heel.
Now he strode through the arched doorway to the path beyond, turned to the left and made for the kitchen steps, Bernard at his heels. With the aid of his torch he picked up, on the second step, a moist heel-print. He glanced triumphantly at Bernard, whose bending face was visible in the refracted rays of the torch. Bernard felt rather than saw the glance and chuckled.
“Well, what about the back stairs?”
“Some people are hard to please,” said Landis thoughtfully. But he entered the back door, turned to the back stairs and began to study the treads carefully.
Half way to the second floor he pounced upon and showed Bernard a fragment of wet mud, irregular on three sides, smooth and flat and slightly concave on the fourth, as though the pile of the carpet had forced it from the front of a heel.