Diana Prince, in present-day Paris, receives a World War I-era photographic plate couriered by Wayne Enterprises and recalls her past.
Diana was raised on the hidden island of Themyscira, home to the Amazon race of warrior women created by the gods of Mount Olympus to protect humankind. In the distant past, Ares, the god of war, slew all his fellow gods, but his father, Zeus, struck him down. Before succumbing to his injuries, Zeus left the Amazons a weapon capable of killing his renegade son: the “Godkiller”, presented as a ceremonial sword. Queen Hippolyta, Diana’s mother, believes that Ares will never return and forbids Diana from training as a warrior, but Diana and her aunt General Antiope defy the queen and begin training in secret. When the two are discovered by Hippolyta, Antiope convinces her sister to allow Diana’s training to continue.
As a young woman in 1918, Diana rescues American pilot Captain Steve Trevor after his plane crashes off the coast of Themyscira. The island is soon invaded by the landing party of a German cruiser pursuing Steve. The Amazons engage and kill all of the German sailors, but Antiope dies intercepting a bullet meant for Diana. Interrogated with the Lasso of Hestia, Steve reveals that “The War to End All Wars” is raging in the outside world, and that he is an Allied spy. He has stolen a notebook with valuable information from the Spanish chief chemist Isabel Maru, who is attempting to engineer a deadlier form of mustard gas under the orders of General Erich Ludendorff from a weapon facility in the Ottoman Empire. Believing Ares is responsible for the war, Diana arms herself with the sword and leaves Themyscira with Steve to find and destroy Ares.