In deep space, Ivanova (Claudia Christian) waits for the First Ones. She wants to get back to the Battle of Coriana VI, but First One Lorien (Wayne Alexander) is calm as always. Finally, an alien ship arrives. Meanwhile, Captain Sheridan (Bruce Boxleitner) leads a fleet of White Star ships to attack a Vorlon post. It is destroyed and they advance on Coriana VI. He and Delenn (Mira Furlan) marvel at the sight of thousands of ships sent by two dozen races under their command. His orders: Take us into the fire.
Marcus Cole (Jason Carter) and Lyta Alexander (Patricia Tallman) discuss the upcoming battle. The battle takes place here rather than at Centauri Prime because Coriana is more helpless. Londo (Peter Jurasik) is taking steps to save Centauri Prime. He is forcing the hesitant Centauri to expel the Shadows and demands that Morden (Ed Wasser) be found. Delenn hears that Ivanova is back at Babylon Five. Sheridan orders her to haul ass to the front, much to Delenn’s amusement.
Before leaving, Ivanova speaks to Lorien about the almost immortal First Ones nurturing the Vorlons and Shadows. Only the younger races, he says, with their shorter lives, can appreciate life. Londo learns that the death of his beloved Adira Tyree, long thought orchestrated by Lord Refa, was actually ordered by the late Emperor Cartagia, but arranged by Morden.
Ivanova is impatient to get into battle. Lorien says the battle will be decided when Sheridan “knows what he knows.” The fleet gathers in the Coriana system, thermonuclear bombs are seeded in the asteroids. Morden is brought to Londo, who has guards kill the two invisible Shadow companions that accompany him. Londo orders him to remove the Shadow vessels on the island base, which are attracting the Vorlons, and Morden resists, knowing the Centauri cannot do that themselves. “What are you going to do? Blow up the island?” Londo pulls a detonator out of his pocket and presses the button. Then he orders Morden dragged off to execution.
Ivanova makes it to the fleet on time. The Shadows and the Vorlons arrive. Sheridan gets their attention with thermonuclear bombs, but the Planet Killer is still headed for Coriana VI. In the garden at Centauri Prime, Vir sees Morden’s head on a pike and waves to him. Back at the battle, the First Ones close in on the Planet Killer. Londo breathes a sigh of relief, but a Planet Killer shows up and Londo realizes there is still one Shadow contact on Centauri—himself. Londo orders Vir to kill him, but the Vorlons recall the Planet Killer back to the battle at the last minute.
A voice speaks through Lyta Alexander (Patricia Tallman) and Sheridan and Delenn are trapped in a blue energy field. Lennier tries to help, but Lorien stops him. They are spoken to by Vorlons and Shadows. The entire Army of Light is enveloped in a death cloud. Sheridan says the younger races know the truth now. The Shadows and the Vorlons should leave the galaxy with the rest of the First Ones. One by one, the old races disappear, Lorien last, leaving the galaxy to the younger races. Londo and Vir prepare to leave the unhealthy Imperial Court and return to Babylon Five. Sheridan and Delenn discuss the coming Third Age of the Galaxy.
The phrase spoken here and used in later episode openings: Now get the hell out of our galaxy. The major feature of the episode is the monumental space battle. Someone pointed out that Morden always asked people what they wanted, but only Vir got what he wanted in the end—Morden’s head on a pike. Thanks to the network’s dithering about ordering a fifth season of Babylon Five, the big climax came in the middle of the fourth season, with a year and a half still to go.