But the throb of the train set the interrogation at the end of the string of names.  So that the sequence of them was like a question demanding confirmation....

Towards three in the morning, when there was no movement in the corridor and the lights were blue and dim, Hillyard silently folded back his bedclothes and rose.  In the darkness he groped gently for the door of the lavatory between his compartment and the compartment of the manufacturer of Perpignan.  He found the handle, and pressed it down slowly; without a creak or a whine of the hinges the door swung open towards him.  Through the clatter he could hear that the manufacturer of Perpignan was snoring.  But Hillyard did not put his trust in snores.  He crept with bare feet across the washing-room, and, easing over the handle of the further door, locked the manufacturer out.  Again there had been no sound.  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.  But there was no note of interrogation now.

“Berlin ...  Berne ...  Paris ...  Cerbere ...  Barcelona ...  Madrid ...  Aranjuez and the world”; and with a thump the train set a firm full stop to the sequence.  Across the broad plain, meadowland and plough, flower-garden and fruit the train thundered down to the Pyrenees.  Paris was far away now, and the sense of desolation at quitting it quite gone from Hillyard’s breast.

“Berlin ...  Berne ...  Paris ...  Cerbere ...  Barcelona ...  Madrid.”

Here was one of the post-roads by which Germany reached the outer world.  Others there were beyond doubt.  Sweden and Rotterdam, Mexico and South America—­but here was one, and to-morrow, nay, to-day, the communication would be cut, and Germany so much the poorer.

The train steamed into Cerbere at one o’clock of the afternoon.

“Every one must descend here, monsieur, for the examination of luggage and passports,” said the attendant.

“But I am leaving France!” cried Hillyard.  “I go on into Spain.  Why should France, then, examine my luggage?”