During World War I, the British troops are entrenched at Passchendaele, Belgium. Amongst the volunteers, there is a young British soldier, Private Arthur James Hamp (Sir Tom Courtenay), who is the sole survivor of his original company. Hamp spent three years in the trenches, and this makes him a veteran. He has never been accused of cowardice, but one day, he simply decides to leave the war behind him and walk all the way home to Britain. In Calais, France, he is challenged by a Military Police patrol, who promptly arrests him for leaving without permission. Hamp’s commanding officers decide to convene a court-martial and charge him with desertion. If found guilty, Hamp could be shot by a firing squad. Captain Hargreaves (Sir Dirk Bogarde) is assigned to be Hamp’s defending attorney, but he seems skeptical about the deserter’s chances of acquittal. During their first talk, Captain Hargreaves is impressed by his client’s utter sincerity and naivete. He learns that his client volunteered on a dare by his friends back home, spent three years in the front-line trenches, remained sole survivor of his company, and that he decided to leave the war and return home. When Hargreaves asks Hamp why he decided to leave the war, Hamp simply says that he got tired of watching his comrades die, and that the noises of war made him sick. On top of that, Hamp argued he received news from home about his wife’s unfaithfulness. All of these reasons made him want to leave the war behind and return home to England. Captain Hargreaves remains unsympathetic. The military doctor’s report indicated that deserter Hamp does not suffer from shell-shock and Captain Hargreaves accepts that fact. However, suspecting that his client’s case is a more complex and peculiar case, Captain Hargreaves believes that Hamp is not responsible for his actions. He prepares the best he can for the upcoming court-martial.