He shut the door of his own compartment lest the swing of the train should set it banging and arouse the sleepers.

Towards the corridor there was a window of painted glass, and through this window a pale, dim light filtered in.

Hillyard noticed, for the first time, that a small diamond-shaped piece of the coloured glass was missing, at about the level of a man's head.

It was advisable that Martin Hillyard should be quick--or he might find the tables turned.

With his ears more than ever alert, he set up the steps for the upper berth, in the lavatory, and whilst he worked his eyes watched that little aperture at the level of a man's head, which once a diamond-shaped piece of coloured glass had closed....
The door of the manufacturer was unlocked, the steps folded in their place, and Hillyard back again in his bed before two minutes had passed.
And once more the throb of the train beat into a chain of towns which went backwards and forwards like a shuttle in his brain.