Early in 1918, Nash began working in oils for the first time. The first oil painting he made was "The Mule Track" in which, amidst explosions from a bombardment, are the tiny figures of soldiers trying to stop their pack animals charging away along another zig-zagging duckboard. Switching to oils allowed Nash to make far greater use of colour and the explosions in "The Mule Track" contain yellow, orange and mustard shades. The canvas "The Ypres Salient at Night" captures the disorientation caused by the changes in direction of the defensive trenches at the Front, which Nash would have been familiar with, and which was exacerbated at night by the constant explosion of shells and flares.