Here a scratch on the metal drew his attention.

Closely he scrutinized this scratch.

A hint of whitish metal told the tale--metal the Master recognized as having been abraded from a ring the Master himself had given him; a ring of aluminum alloy, fashioned from part of a Turkish grenade at Gallipoli.
The Master's face contracted painfully.

In his mind he could reconstitute the scene--Rrisa's hands gripping the rail, his climb over it, his leap.

For a moment the Master stood there with blank eyes, peering out over the burning, tawny desolation of the great sand-barrens that stretched away, away, to boundless immensity.
"Yes, he is surely gone," he whispered.