Figures loomed up unexpectedly out of the mist; occasionally a low curse could be heard as a man stumbled into a shell hole. . . .
"Everything all right; everybody clear?" The gas expert peered at Vane in the darkness. "Right! well, let her go."
A series of reports sounded deafeningly loud, as the detonators of the cylinders were fired by electricity; a steady, hissing noise as a great wall of white vapour mingled with the mist and rolled forward towards the Germans. The gas attack had begun. To an airman returning from a bombing raid, who circled for a moment above, it looked like a sheet being slowly spread over the country below; a beautiful--an eerie--picture. To those on the ground who watched it, it seemed as a so