Resident Evil 0 Story Explained: Plot Summary and Ending

Resident Evil 0 came out on the GameCube in November 2002 and was remastered in HD in 2016. It's a prequel: the earliest main game in story order, set on 23 July 1998, the night before the original Resident Evil. It follows Rebecca Chambers, the rookie medic of S.T.A.R.S. Bravo Team, and a convicted Marine named Billy Coen, and it shows where the t-Virus came from. This page covers the whole plot and the ending, so it has full spoilers. (Resident Evil 0)

Before the story begins#

The Umbrella Corporation looked like a drugs company. In secret it was building biological weapons in the forests outside Raccoon City. Its executive training school in the Arklay Mountains had been closed for about twenty years, and its old director, Dr. James Marcus, one of Umbrella's founders, had been dead for ten. Through the summer of 1998, people around the mountains were being killed and partly eaten. The Raccoon police couldn't solve it, so the case went to S.T.A.R.S., the department's special tactics unit. That's all you need going in. (Resident Evil 0; Resident Evil)

The Ecliptic Express#

On the evening of 23 July, the Ecliptic Express, an Umbrella train full of staff, was crossing the Arklay Mountains when a swarm of leeches burst through the windows. A young man watched from a hilltop, singing. About two hours later, Bravo Team's helicopter developed engine trouble and came down in the forest. While the pilot, Kevin Dooley, stayed behind to fix it, Captain Enrico Marini and his five officers found an overturned military police truck nearby. The two MPs were dead, and their prisoner was gone. (Resident Evil 0)

That prisoner was Second Lieutenant Billy Coen, a Marine on his way to execution for the murder of 23 people. Enrico had the team split up to find him. Rebecca found the stopped train instead. Its passengers were dead and then not dead, and at the front she found Billy himself, armed and refusing to go quietly. Her teammate Edward Dewey crashed in through a window, badly mauled, warned of monsters and died. Infected dogs followed him in. (Resident Evil 0)

Rebecca and Billy didn't trust each other, but neither could get off the train alone. In the dining car a passenger turned out to be nothing but leeches wearing a human shape, and Billy saved her from it. From the windows they saw the singing man again. (Resident Evil 0)

Then the train began to move. Umbrella had sent a security team to take control of it, and the leeches killed that team too. With no one at the controls, the Ecliptic Express picked up speed. Rebecca and Billy worked the brakes at both ends, and Rebecca had to put down Edward, who had come back as a zombie. They slowed the train but couldn't stop it. It ran off the line into an underground station and derailed. (Resident Evil 0)

The training school#

The station belonged to Umbrella's old executive training school. Two Umbrella researchers, Albert Wesker and William Birkin, were watching on CCTV when the singing man cut into their feed and accused them of betraying Marcus, of releasing the virus at the Arklay Laboratory and of the train. The two men concluded they were dealing with Marcus somehow come back, and decided to blow the whole facility up with him in it. (Resident Evil 0)

Inside, Rebecca and Billy found what the school had really been for. It had trained gifted young recruits, and Marcus had used some of them as test subjects. There was a torture room in the basement, the halls were full of zombies, some of them those children, left there for twenty years, and others the investigators Umbrella had recently sent to refurbish the place. Documents showed Marcus had fallen out with Umbrella's president, Oswell E. Spencer, who wanted his research on the Progenitor virus and the t-Virus for himself. (Resident Evil 0)

The singing man spotted Rebecca on camera and set Marcus's mutant apes on her. After Billy pulled her out of one fight too many, she demanded the truth about him, and he told her. His unit had been sent after a guerrilla base in Africa on bad intelligence and taken losses. Their commander ordered them to shoot the people of a village. Billy refused, and the others made him the scapegoat at his court martial. Rebecca believed him. (Resident Evil 0)

Marcus's laboratory#

Beneath a ruined church was Marcus's old laboratory. It was worse than the school: human bodies in tanks, harvested organs, an overflowing morgue and an operating theatre covered in blood. In Marcus's study Billy found a photograph of the scientist as a young man. He was the double of the singing man, and Billy guessed he must be a son or grandson. (Resident Evil 0)

On the way out, one of Marcus's creatures attacked them on a cable car platform and Billy fell into an underground river. Rebecca went on alone to the nearby chemical plant and down a huge lift into a second Umbrella complex. There she ran into Enrico, who had come in through a tunnel from the direction of a mansion in the woods. He wanted her to come back with him and regroup. She refused to leave without Billy, and he let her go. Soon after, she was attacked by a prototype Tyrant, let loose in the chaos the leeches caused, and fought it off. (Resident Evil 0)

The treatment plant and the Queen Leech#

Rebecca found Billy washed up in the water treatment plant, alive, on a walkway covered in skeletons. Marcus had been dumping his test subjects in the water for years. Further in, they finally met the singing man face to face, and he told them what he was. (Resident Evil 0)

He wasn't Marcus or his son. He was the Queen Leech, a creature Marcus had bred. In 1988 Spencer had Marcus assassinated so Umbrella could take his work, and Wesker and Birkin were sent to collect the data. Marcus's body was thrown into the water with his leeches. The Queen Leech fed on it and absorbed his memories, and over the years it came to believe it was Marcus, brought back to punish Umbrella and burn the world. (Resident Evil 0)

It dropped the human shape and became a huge leech monster. Rebecca and Billy escaped up a cargo lift to the surface, and it followed them into a warehouse on the plateau. Realising light hurt it, Rebecca opened the roof to the sun. Billy shot it with a magnum and it fell down the lift shaft as the self-destruct went off and the treatment plant and training school exploded. (Resident Evil 0)

The ending explained#

Rebecca and Billy came out on a clifftop as the sun rose. From there Rebecca could see the mansion Enrico had mentioned, where the rest of her team must be. That left Billy. As an escaped prisoner under sentence of death, he'd be executed if she brought him in. So she took his dog tags and told him that, as far as she was concerned, Lieutenant Billy Coen was dead. He thanked her and walked off into the forest. (Resident Evil 0)

The ending answers the game's two big questions. The "Marcus" Umbrella feared was a leech wearing his memories, and the murders in the mountains trace back to Umbrella's own crimes: Marcus experimenting on recruits, and Spencer killing him for it. It also leaves Wesker and Birkin alive and plotting. The attack on the train was the moment Umbrella understood someone was infecting its people on purpose, and Wesker still had a S.T.A.R.S. operation to run at the mansion. (Resident Evil 0)

Billy's fate is left open. He doesn't appear in the original Resident Evil, and the game gives no hint of where he went. (Resident Evil 0; Resident Evil)

What it sets up#

Rebecca walks out of Resident Evil 0 and into the original Resident Evil, where Alpha Team arrives the next night looking for her squad and finds the Spencer Mansion. Enrico, last seen heading that way, is waiting in the tunnels under it. For where both games sit among everything that followed, see the Resident Evil timeline and the series overview in Resident Evil story explained. (Resident Evil 0; Resident Evil)