By means of the landing window, the superintendent found his way without much difficulty out on to the roof, and was easily able to climb over its gabled side to the flat space in the centre. And there at last his efforts were rewarded; for on the roof lay, clearly just where it had been thrown, a small bag heavily loaded, not with sand, but with small shot—a deadly weapon. Stuffing the thing into his pocket, the superintendent climbed back with more difficulty, and shut the window behind him. He chuckled softly to himself. He had reasoned aright, and here at last was a clue that had not been laid to mislead—a real clue that he must make to point straight at the murderer. He went back to his office to examine his find at leisure. Chapter XXXIV The Stable-Yard While Superintendent Wilson, by his own methods, was thus working towards the solution of the mystery, Joan and Ellery were also pursuing their investigations along their separate line. There was but one thing needed, they felt, to complete their case, and turn their conviction from moral into legal certainty. How had Woodman got into Liskeard House? That was the question which Joan had set herself to answer. The coach-yard seemed to be the only possible means of access. It was a large square yard opening into Liskeard Street by a pair of massive wooden doors ten feet high, and a small gate let into the wall at the side. Neither the wall nor the doors could be climbed without the aid of a long ladder. One entering by these doors would find himself in the yard. On his left he would have the side wall of Liskeard House, which had no window looking out on to the yard. On his right would be the large coach-house, now used as a garage, above which lived the chauffeur and his wife, formerly a domestic of Sir Vernon’s—both servants of long standing. Their apartment had also a door opening into Liskeard Street, and a way down into the garage. Immediately opposite any one entering the yard from the street was an extension, built out from the side of Liskeard House towards the back. The ground floor of this was occupied by store-rooms, accessible only from the yard; but between these a passage led through directly into the garden. Above were rooms belonging to Liskeard House, whose windows looked out only upon the garden.