The messenger whom Blick had sent into Selcaster that morning, before he himself went up to Markenmore Court to attend the Coroner’s inquest, had carried a letter to the principal bookseller and stationer in the old city. There were certain things that Blick found himself in great need of in tackling the problems which had just been put before him; the bookseller was the man to supply him. And now here were the bookseller’s parcels—one, a long, rolled thing, carefully wrapped in canvas; the other a fat little parcel in brown paper. Blick undid that first and drew out and laid on his table a folding road map, a general map of the county, two or three local guide-books, illustrated by photographs, a more ambitious work, _Environs of Selcaster_, also full of pictures, a Bradshaw’s Railway Guide, and a local time-table. He looked over all these carefully as he laid them out—they were just what he wanted. But he felt still greater interest in the long, canvas-covered parcel, which, divested of its wrappings, proved to contain the Government Ordnance Map of the Markenmore village and immediate surroundings—a big square thing, on stout paper, wherein every road, bylane, footpath, house, cottage, meadow, wood, field, coppice, river, stream, hedgerow, stile, was marked, named, and measured. Blick’s detective instincts rejoiced at the sight of that masterly performance—he blessed the men of the Ordnance Survey service for their meticulous care in preparing it. Going out in search of Grimsdale, he procured some tin tacks from him; with these he fastened his Ordnance Map to a convenient blank space on the wall of his sitting-room, and for the next half-hour stood smoking his pipe in front of it. At the end of that time he had memorized the general lie of his surroundings and committed the more important place-names to the secret cells of his quick brain.