"I had forgotten my letters." And he rose from his seat at the table, mounted the steps, and passed into the mess-room.
Calder immediately sprang up, and with his eyes followed Durrance's movements.

Durrance went to a nail which was fixed in the wall close to the glass doors and on a level with his head.

From that nail he took down the key of his office, crossed the room, and went out through the farther door.

That door he left open, and Calder could see him walk down the path between the bushes through the tiny garden in front of the mess, unlatch the gate, and cross the open space of sand towards his office.

As soon as Durrance had disappeared Calder sat down again, and, resting his elbows on the table, propped his face between his hands.
Calder was troubled.