Suddenly from just in front of me came a familiar sound.  It was the roar of guns—­the slam of field-batteries and the boom of small howitzers.  I wondered if I had gone off my head.  As I plodded on the rattle of machine-guns was added, and over the ridge before me I saw the dust and fumes of bursting shells.  I concluded that I was not mad, and that therefore the Germans must have landed.  I crawled up the last slope, quite forgetting the pursuit behind me.

And then I’m blessed if I did not look down on a veritable battle.

There were two sets of trenches with barbed wire and all the fixings, one set filled with troops and the other empty.  On these latter shells were bursting, but there was no sign of life in them.  In the other lines there seemed the better part of two brigades, and the first trench was stiff with bayonets.  My first thought was that Home Forces had gone dotty, for this kind of show could have no sort of training value.  And then I saw other things—­cameras and camera-men on platforms on the flanks, and men with megaphones behind them on wooden scaffoldings.  One of the megaphones was going full blast all the time.

I saw the meaning of the performance at last.  Some movie-merchant had got a graft with the Government, and troops had been turned out to make a war film.  It occurred to me that if I were mixed up in that push I might get the cover I was looking for.  I scurried down the hill to the nearest camera-man.

As I ran, the first wave of troops went over the top.  They did it uncommon well, for they entered into the spirit of the thing, and went over with grim faces and that slow, purposeful lope that I had seen in my own fellows at Arras.  Smoke grenades burst among them, and now and then some resourceful mountebank would roll over.  Altogether it was about the best show I have ever seen.  The cameras clicked, the guns banged, a background of boy scouts applauded, and the dust rose in billows to the sky.

But all the same something was wrong.  I could imagine that this kind of business took a good deal of planning from the point of view of the movie-merchant, for his purpose was not the same as that of the officer in command.  You know how a photographer finicks about and is dissatisfied with a pose that seems all right to his sitter.  I should have thought the spectacle enough to get any cinema audience off their feet, but the man on the scaffolding near me judged differently.  He made his megaphone boom like the swan-song of a dying buffalo.  He wanted to change something and didn’t know how to do it.  He hopped on one leg; he took the megaphone from his mouth to curse; he waved it like a banner and yelled at some opposite number on the other flank.  And then his patience forsook him and he skipped down the ladder, dropping his megaphone, past the camera-men, on to the battlefield.

That was his undoing.  He got in the way of the second wave and was swallowed up like a leaf in a torrent.  For a moment I saw a red face and a loud-checked suit, and the rest was silence.  He was carried on over the hill, or rolled into an enemy trench, but anyhow he was lost to my ken.