Although she initially forbids Diana to be trained as a warrior, Hippolyta reluctantly agrees to let General Antiope, Hippolyta's sister and Diana's aunt, train her, only more rigorously than any other warrior. In 1918, Diana, now a young woman, rescues US pilot Captain Steve Trevor when his plane crashes off the Themysciran coast. The island is soon invaded by German soldiers that had been pursuing Trevor. The Amazons kill the crew, but Antiope sacrifices herself to save Diana. Steve is interrogated with the Lasso of Hestia and reveals that a great war is consuming the outside world and that he is an Allied spy. He has stolen a notebook of the chief chemist Dr. 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 to be responsible for the war, Diana arms herself with the "Godkiller" sword, the lasso, and armor before leaving Themyscira with Steve to locate and stop Ares for good.
In May 2017, early tracking had Wonder Woman opening with $65–75 million, and possibly as high as $105 million. The film opened Friday, June 2, 2017, across 4,165 theaters and made $38.7 million on its opening day, including $3.7 million in IMAX. It was the biggest single-day gross for a woman-directed film, ahead of the $35.9 million opening Friday of Catherine Hardwicke's Twilight in 2008 and the biggest opening day for a woman-led comic book superhero film, ahead of Ghost in the Shell ($7 million). This included $11 million it made from Thursday previews, also the best start for a film directed by a woman, surpassing Fifty Shades of Grey's $8.6 million which was directed by Sam Taylor-Johnson, and the third-biggest of the year, behind Beauty and the Beast and Guardians of the Galaxy Vol. 2. Of that, $1.5 million came from IMAX screenings.