"LAND MINE EXPLOSION Officers of the Royal Engineers receive instruction in
exploding land mines". Military exercise. Three men in trench, one turning a handle. Men run out of shelter along trench. Three officers look out of trench, then duck. Long shot of explosion. Two men put on gas masks, pick up canaries in boxes and enter shelter (notice above entrance reads 'Baby
Mine').
Note: Story continued in OCCUPYING THE CRATER.