 Complete the following phrase:  On 12 March 1918, as the Germans prepared to launch their Spring Offensive, they laid down a heavy mustard gas barrage on Dempseys battalion, which was now at La Vacquerie with Dempsey commanding D Company. Dempsey, along with 10 officers and 250 other ranks, was gassed and later evacuated to England, where he had a lung removed. He returned to the battalion on 6 July, where, with the tide of the war having turned, the 1st Royal Berkshires took part in the Hundred Days Offensive until the war ended on 