A second, a more conscientious girl, corrected her.

“At least,” she said, “you may go through B.”

“I should think,” said the third, “that through B. is as likely a way as any. Will you take a letter for us? It’s most important and the post takes ages. You’ve only got to hand it to any of our people you see on the platform or drop it in at any of our canteens. It will be delivered all right.”

Who “our people” or what “our canteens” might be I did not at that time know. It was our fellow-traveller who offered to take the letter.

“I’m not exactly going to B.,” he said; “but I expect I’ll fetch up there sooner or later.”

The letter was given to him. The young women, profuse in their thanks, sprang from the train just as it was starting. Our fellow-traveller told me that our visitors belonged to the Y.M.C.A. I was not, even then, much surprised to find a Young Men’s Christian Association run chiefly by young women, but I did wonder at this way of transmitting letters. Afterwards I came to realise that the Y.M.C.A. has cast a net over the whole war area behind the lines, and that its organisation is remarkably good. I imagine that the letter would have reached its destination in the end wherever our fellow-traveller happened to drop it. I suppose he took the same view. His responsibility as a special messenger sat lightly on him.

“I may spend the night at B.,” he said, “or I may get into the Paris express by mistake. It is very easy to get into a wrong train by mistake, and if I once get to Paris it will take me a couple of days to get away again. I’m not in any kind of hurry, and I deserve a little holiday.”

He did. He had been in the trenches for months and was on his way to somewhere for a course of instruction in bombing, or the use of trench mortars, or map-reading. In those days, early in 1916, the plan was to instruct young officers in the arts of war after they had practised them, successfully, for some time. Things are much better organised now. Trains are no longer boarded by young women with letters which they wish to smuggle through uncensored. It is difficult to get into the Paris express by accident. But courses of instruction are still, I imagine, regarded by every one, except the instructors, as a way of restoring officers who are beginning to suffer under the strain of life in a fighting battalion. A holiday frankly so-called, in Paris or elsewhere, would be better; but a course of instruction is more likely to meet with the approval of a general.