“It seems that it used to be, many years ago--for the slaves. You will remember that you remarked the sunken spots in the only bit of soft earth there is, and wondered what made them. They are graves. Do you suppose Rucker would sleep any better to-night than he did last night if he knew that? If he had known it last night, perhaps it might have accounted for some of his restlessness. But I’m drifting from the point, which is that Miss Richardia’s question betrayed her: she was the young woman who drove with the man behind the white horse; otherwise she would not have known about the location of the drilling plant in the glade.” “That doesn’t follow,” Tregarvon objected. “Some one might have told her. But let that part of it go. Did you discover anything else?” “Yes. After school hours I took Miss Farron, Miss Longstreet, and the French teacher out for a spin in the car. Miss Richardia said she couldn’t go because she had another engagement. We made a rather long round to the south and came back to Highmount by a road which parallels the western brow of the mountain. Are you paying attention?” “Breathless attention,” said Tregarvon ironically. “Joy-ride stories always make me sit up. Go on.” “Over on the west-brow road we passed a place which looked as if it might be--or might some time have been--a gentleman’s country house. It is walled in from the road, with a magnificently groved lawn, a box-bordered, weed-grown carriage drive, and a great, rambling, porticoed mansion needing the repair-man pretty savagely. Still sitting up and taking notice?” “Yes.” “Just as were rolling up to pass the stone-pillared lodge-gates a horse and buggy came out, with a young woman driving. The horse was old and countrified, and he didn’t take kindly to the auto. So I stopped and got out to lead him past the machine. You won’t want to believe it, but the young woman driver was Miss Richardia; and the horse--well, no horseman would call it white, to be sure. It was a dapple-gray, light enough to pass for white in the moonlight, and with a mechanician like Rucker for the color expert.” Tregarvon came out of his listless mood with a snap. “Let it be said, once for all, Poictiers, that I won’t stand for any theory that involves Richardia Birrell in the crooked part of it,” he declared firmly. “I’d trust her with anything I own; with my life, if she cared to borrow it. That dapple-gray suggestion of yours makes my back ache! It isn’t worthy of you. Rucker said ‘white,’ and white isn’t gray; not by a long shot!” “Wait,” said Carfax, evenly. “After I had led the horse safely past the car, I made sure. ‘Hold on a minute, Miss Richardia,’ said I, ‘let me see if your horse hasn’t a pebble in his shoe.’ That gave me an excuse to lift his near hind foot. There wasn’t any pebble, of course, but the shoe was badly worn, _and the toe-calk had a piece broken out of it_!”