"Might have been caught unawares, and pushed over. Let's see what there is up above, anyway."

The stair in the turret, much worn, but comparatively safe, and lighted by loopholes and arrow-slits, terminated in a low arched doorway, through which egress was afforded to a parapet which ran completely round the inner wall of the Keep. It was in no place more than a yard wide; the balustrading which fenced it in was in some places completely gone, a mere glance was sufficient to show that only a very cool-headed and extremely sure-footed person ought to traverse it. Copplestone contented himself with an inspection from the archway; he looked down and saw at once that a fall from that height must mean sure and swift death: he saw, too, that Greyle had been quite right in saying that the sudden plunge of Oliver's body through the leafy screen far beneath had made little difference to the appearance of that screen as seen from above. And now that he saw everything it seemed to him that the real truth might well lie in one word—accident.

"Coming round this parapet?" asked Gilling, who was looking narrowly about him.

"No!" replied Copplestone. "I can't stand looking down from great heights. It makes my head swim. Are you?"

"Sure!" answered Gilling. He took off his heavy overcoat and handed it to his companion. "Mind holding it?" he asked. "I want to have a good look at the exact spot from which Oliver must have fallen. There's the gap—such as it is, and it doesn't look much from here, does it?—in the green stuff, down below, so he must have been here on the parapet exactly above it. Gad! it's very narrow, and a bit risky, this, when all's said and done!"

Copplestone watched his companion make his way round to the place from which it was only too evident Oliver must have fallen. Gilling went slowly, carefully inspecting every yard of the moss and lichen-covered stones. Once he paused some time and seemed to be examining a part of the parapet with unusual attention. When he reached the precise spot at which he had aimed, he instantly called across to Copplestone.

"There's no doubt about his having fallen from here!" he said. "Some of the masonry on the very edge of this parapet is loose. I could dislodge it with a touch."

"Then be careful," answered Copplestone. "Don't cross that bit!"

But Gilling quietly continued his progress and returned to his companion by the opposite side from which he had set out, having thus accomplished the entire round. He quietly reassumed his overcoat.

"No doubt about the fall," he said as they turned down the stair. "The next thing is—was it accidental?"