In Kansas, as small spacecraft crashes to earth, on the Kent farm. Jonathan and Martha Kent approach the pod, and open it up. The Kents find a baby inside. As they attempt to retrieve it, someone electrocutes them both from behind, killing them. A woman retrieves the baby, while the man who electrocuted the Kents zaps them both again, making sure they’re dead.
Several years later, Thomas and Martha Wayne, with their son, Bruce, leave the movie theater at night after seeing the Mark of Zorro. They are accosted in Crime Alley by a mugger, Joe Chill, who shoots Thomas and Martha dead. He fires again, but suddenly, the bullets are manipulated by an unknown force, and fly straight back at Chill, flying clean through him, killing him. A man steps out of the shadows, this man having directed the bullets’ paths. He offers Bruce a better life, and takes him away. The three people who changed the lives of the baby and Bruce Wayne continue to alter history, killing potential heroes before they either got their powers or assumed their identities.
Lois Lane wakes up in her room, and walks into the bathroom, where Clark Kent is shaving. He greets Lois, and the two embrace. In Wayne Tower, Bruce finishes putting on his suit and Selina Kyle finishes changing as well. They kiss and say goodbye, and Selina leaves, the two having apparently spent the night together. Bruce sits inside the tower with a cigarette, and looks out at the monument to Superman and Batman in the city. Clark arrives, and the two get to talking. By the monument, people are being herded through the city.
Outside, in an alley, a young people gets attacked by a group of soldiers. Green Arrow shows up, and takes out the men. The man tells Green Arrow to look up in the sky, and Arrow says that he hates when people say that. He turns to see Superman and Batman behind him, both having been tracking him for a while now. Green Arrow remarks that Superman an Batman should be off pressing a country, and he fires an arrow at Superman. Superman catches the arrow, remarking that it was stupid of Arrow to try to take Superman down so easily. However, the arrow explodes with kryptonite radiation, and Green Arrow replies that maybe it wasn’t so stupid after all.
Batman, enraged, that Superman may have been hurt, attacks Green Arrow. Green Arrow clocks Batman in the head with his bow, sending him careening into a few garbage cans. Batman gets up, and delivers a volley of punches and kicks to Green Arrow. Green Arrow sticks Batman in the arm with an arrow tip, and Batman brutally kicks Green Arrow in the face again. Before Green Arrow can recover he is disintegrated by a blast of heat vision from Superman, who tells him that he will either obey, or die.
Later that day, Batman and Superman teleport up to the JLA Watchtower, where they meet their “parents”, the people who intervened in their origins all those years ago, Cosmic King, Saturn Queen, and Lightning Lord. Today is apparently Superman’s birthday, and they light candles on a birthday cake for him to celebrate.
Meanwhile, it’s night time on earth, and a woman is shot at by soldiers for being out after curfew. The woman blocks the bullets with her bracelets, and deflects them back at the men, killing or wounding them. She enters a subway, and finds a homeless man sleeping there. She picks him up, and tells him that the world needs him. He tries to get away from her, but she uses the golden lasso around her waist and ties him up in it. He transforms in a flash of blind light, and becomes the hero, Uncle Sam. He tells her that she’s probably right about the world needing him, and he asks what her name is. She tells him that it’s Diana, and he tells her that the have a long fight ahead of them, and that they’d better start now.