A number of soldiers are shown resting on the roadside awaiting reinforcements to take their position. The ‘Caterpillar’ in the title refers to the name of a sunken road south of Ville-sur-Ancre. Dyson visited Ville-sur-Ancre following its capture by the Australian Imperial Force had captured on 19 May 1918. Dyson recorded that while sketching this scene his friend, Captain George Wilkins, had crept out of the Caterpillar followed by a sustained burst of machine gun fire which lasted long enough for Dyson to complete his drawing. Dyson was frequently in the thick of the action and in November 1917 was sent to London to rest and recover after being wounded.