The first trailer for Sam Mendes' epic war drama 1917 was released on Thursday. Starring Benedict Cumberbatch and Colin First as battle-worn military men, the film follows two young soldiers who are tasked with an impossible mission to save the lives of 1600 men. Set in the height of World War I, the intense teaser opens with leads George MacKay and Dean-Charles Chapman entering an underground bunker, supposedly used by their allies who were taken captive.