"Cheero, Jack! Good luck!" "Cheero, Paul!" comes the answer, and the engine leaps out into deafening thunder, and with a beating throb the machine slips by, going ever faster into the night. Soon the last machine has left, and for a time we see the red and green lights moving above us through the stars, and we hear the murmur of the engines, and then at length silence reigns in the quiet uneasy night! To the side of the canal I walk and peer out across the silent plain to the dim east. A pallid star-shell gleams, and quivers, and sinks: a gun flashes to the south near Ypres: then remote, remote, yet glittering clearly, rises a tiny chain of green balls which climbs up, up, up into the night. Near it can just be seen the pale arms of moving searchlights, seeming scarce lighter than the darkness. Already the great night-birds have pierced the frontiers of the enemy: already has the battle of the night skies begun. Then with an unexpected suddenness wails the panic-stricken appealing cry of "Mournful Mary" at Dunkerque docks. Again and again it wails, and its dying echo is taken up by a chorus of shrill and undignified hooters and syrens in the district. What a sense of utter terror there is in the sound! The town seems to have a corporate existence, and seems to be screaming piteously, like some animal faced with a terrible and unavoidable death. Again moans the chilling sound of the great voice of Dunkerque, and down the coast the blue-white beams of the French searchlights begin to wave nervously in an uncertain sweep. Three or four anti-aircraft guns sound dully in the distance, and a few red and futile shells burst high up in the star-strewn sky. More and more searchlights come into action; nearer and louder guns bark out their stupid blind anger. There is little movement in the crowd of watchers on the aerodrome. Every one listens. Faintly yet surely can be heard now the menacing chant of the enemy--bavoom, bavoom, bavoom--steady, unaltering, ever progressing forwards. "Huh! That's old Oberleutnant Finkelbaum from Ghistelles. He's always first!" says a wit. "Come on, Finky ... you won't be found. That's right--keep up the coast. You're after the docks, I suppose. Look out; throttle, man--throttle, or you will get caught!" _Bavoom--bavoom_, throb the two engines of the bold attacker, and our sympathies and interest somehow seem to be with him. "Turn in now, old man, turn in! Stop your engine--that's good--glide and keep throttled--you'll be all right!" Suddenly the droning above ceases, and the silence is more threatening and sinister than the clamour. We do not feel quite so assured about the unseen enemy, since we can no longer locate his position by sound. However, we know that he is almost certain to be attacking the docks, which lie some two miles away, so we do not altogether lose the sense of being spectators.