He had a strong feeling of responsibility towards his little station and its inexplicable tenant, therefore he hurried back against his will.

His only consolation in this backward walk was the key of the door he had locked, which in haste he had taken out and still held in his hand.

Without attempting to decide whether the thing he had seen was of common clay or of some lighter substance, he still did not lend his mind with sufficient readiness to ghostly theory to imagine that his unwelcome guest could pass through locked doors.
Nor did the ghost, if ghost it was, pass through unopened doors.

The flaw in Trenholme's comfortable theory was that he had forgotten that the large double door, which opened from the baggage room to the railway track, was barred on the inside.

When he got back to his place he found this door ajar, and neither in his own room, nor in the baggage room, nor in the coffin, was there sign of human presence, living or dead.
All the world about lay in the clear white twilight.