It depicts the aftermath of a mustard gas attack during the First World War, with a line of wounded soldiers walking towards a dressing station.

Biplanes dogfight in the evening sky above, as a watery setting sun creates a pinkish yellow haze and burnishes the subjects with a golden light.

In the background, the moon also rises, and uninjured men play association football in blue and red shirts, seemingly unconcerned at the suffering all around them.

[3][1] The plan was a complement to the artworks commissioned by the Canadian War Memorials Fund since 1916 at the instigation of Lord Beaverbrook, who, by 1918, was serving as the British Minister of Information.

The plan for a Hall of Remembrance decorated by large paintings was abandoned when the project was incorporated with that for Imperial War Museum.

Excepting at night I have only seen three fine subjects with masses of men – one a harrowing sight, a field full of gassed and blindfolded men – another a train of trucks packed with "chair à cannon" – and another frequent sight a big road encumbered with troops and traffic, I daresay the latter, combining English and Americans, is the best thing to do, if it can be prevented from looking like going to the Derby.

[6] Tonks described the experience in a letter from to Alfred Yockney on 19 March 1920: After tea we heard that on the Doullens Road at the Corps dressing station at le Bac-du-sud there were a good many gassed cases, so we went there.

They sat or lay down on the grass, there must have been several hundred, evidently suffering a great deal, chiefly I fancy from their eyes which were covered up by a piece of lint.... Sargent was very struck by the scene and immediately made a lot of notes.

As the unfortunate victims were being helped, practically blinded, by their comrades on a field ambulance, John Sergeant happened to arrive on the scene.

Shortly before he had told me that he had been commissioned to paint a picture which should be typical of the war, and I suggested 'tanks,' they being the latest military machine and a novel feature of it."

The War Memorials Committee agreed to change the subject of the commission, and the painting was created at Sargent's studio in Fulham from late 1918 to early 1919.