During the First World War young British soldiers prepare for an attack. The film depicts the days in the trenches just before the Battle of the Somme in 1916 and shows the emotional experiences of the soldiers in the narrow trenches, an experience that ranges from boredom to fear, from panic to unrest. Billy MacFarlane (Paul Nicholls), 17, volunteered for service with his older brother Eddie (Tam Williams). The entire platoon, all in their late teens, depends on the war-tested Sergeant Winter (Daniel Craig) and the learned Lieutenant Hart (Julian Rhind-Tutt) for their survival. When news arrives that the platoon will join the first wave of attacks, they do not know that they will be there when the British Army loses the largest number of soldiers in a single day in its history.