Tom Andersley returns to his family estate in Yorkshire after serving in France throughout the Great War of 1914-18, but like many of his fellow survivors he finds the estate very different and is not the same man who departed: a victim of shell shock. Unable to reconnect with his wife and daughter, who have endured traumatic experiences of their own, he retreats obsessively into his old hobby, entrenching himself in his greenhouses in order to carry out meticulous experiments in the cross-breeding of fruit trees. He is interrupted in his existential paralysis by the mysterious arrival of an old friend from Eton, Lawrence Oates, whom everyone believes to be dead, having walked out of Robert Scott's tent in an Antarctic blizzard in 1912 in order not to slow down his companions in their doomed attempt to reach safety.