Babylon 5

Teaser: A spaceship approaches Babylon 5 from deep space, travelling without using the Jumpgate. Ivanova alerts Sheridan and they both listen to the signal being transmitted over and over from the ship: "This is the Copernicus. We come in peace." The signal is in English. At the same time in Downbelow one of the human lurkers, Amis, jumps out of a container raving about "It" coming though the walls. He grabs his chest in pain, then his head and seems to be looking for something. Between ranting and prayers he finally presses his face to a small window. Looking out into the darkness of space he cries: "There you are!"

Title Sequence

Amis is standing on the counter of one of the bars warning an annoyed crowd about the coming of the Apocalypse. He approaches both G'Kar and Londo, making them both run away. Finally Garibaldi grabs Amis gently and places him under arrest for preaching without the proper missionary license. Garibaldi then joins Ivanova and Sheridan in the bridge. One of the maintenance bots has reached the Copernicus and begins to scan it. The outer shell is in bad shape and the full name of the ship is almost erased. Only Sheridan recognises the letters as saying U.S.S. Copernicus. This identifies it as one of the ships that left Earth a hundred years earlier, before Earth had Jumpgate technology, to go into deep exploration missions with its crew in cryogenic stasis. While they speculate as to why this one was never recovered, Ivanova detects one life sign still on board. Sheridan decides to bring the Copernicus in.

Dr. Franklin, Ivanova, Garibaldi and Sheridan enter the Copernicus now stored in one of the station bays. Two cryogenic freezers are in view, but one of them contains only a corpse. The second contains a live woman, but her life signal is weakening. Dr. Franklin decides to transport her to Medlab. In the lift, while being carried on a gurney, the woman goes briefly into cardiac arrest and, at the same time, the lights in the lift flicker on and off. Ivanova remains in the ship to check the logs and hears some kind of growl.

Garibaldi checks on Amis, who is sleeping in his cell, and finds him shouting in a nightmare: "Incoming!" Garibaldi recognises it as a symptom of post-traumatic war syndrome, something that he himself has been through as well. When Amis wakes up, he seems to be fully rational but claims to have no memory of what he did. Garibaldi advices him to get some psychiatric help but Amis refuses it and asks to leave, to which Garibaldi agrees. Amis later goes to the bay where the Copernicus is. He recognises something that scares him and he runs away. The woman, Mariah Cirrus, wakes up in Medlab from a nightmare, with Dr. Franklin at her side.

Ivanova has checked the Copernicus' logs and there is no indication of a malfunction in the cryogenic unit of the dead man, whose name was Will Cirrus, Mariah's husband. That means that he was murdered. An autopsy reveals that his body mass was half of what is should have been and that his internal organs are missing. Although the log indicates that Mariah was in stasis the whole time, she is a suspect. Dr. Franklin is now in charge of informing her that she has been asleep for over 100 years and that her husband is now dead. She tries to cry, but her tear ducts are dry from the cryogenic sleep and she mutters "What have I done?" Dr. Franklin brings her to the Zocalo to try to cheer her up. She is fascinated by the alien visitors and sad when she realises that if they had waited a few years the whole cryogenic freeze would have been unnecessary. Dr. Franklin introduces her to G'Kar, but when he takes her hand and advises her to return to her own time, she has some kind or memory recall that frightens her and she faints. Dr. Franklin brings her to his quarters and reveals to her that her husband was murdered. He tries to make her talk about her nightmares, hoping for a clue about the murder. They share a brief romantic moment before she needs to rest again.

Garibaldi is having a meal at the bar when Amis appears, ranting again, but this time he is more rational and tells Garibaldi that a Soldier of Darkness came to the station inside the Copernicus and that he followed it. Garibaldi puts Amis back in cell for the night and checks Amis' war record. He discovers that he was a war hero and the only survivor of an intelligence gathering outpost officially decimated by the Minbari. The outpost was on the flight path of the Copernicus. Amis always claimed that the Minbari were not responsible, but that something came through the walls, only visible through lightning, and that it killed everyone, keeping him alive while feeding on him. He claims that he can feel the Thing because part of him is still inside it. After a failed attempt next day at locating the creature, Amis runs away.

Meanwhile a murder victim appears, also with his internal organs missing. Dr. Franklin vouches for Mariah, but the Babylon 5 Council is called and the Markab ambassador explains that many believe that the ancient enemy has awoken and it is calling his scattered forces back home. Londo mocks these stories as superstitions, but G'Kar encourages them. The Markab ambassador threatens with violence if Mariah, who he thinks could be the "Soldier of Darkness" herself, is not expelled. This prompts Sheridan to exert his authority and silence the ambassador before the situation escalates.

Mariah and Dr. Franklin are back in the Copernicus and she reveals that her marriage was not a happy one and that now she feels guilty for not being as sad as she should be about her husband's dead. Dr. Franklin pleads to her to be frank with him and she finally explains that, in her dreams, something is inside the cryogenic unit with her, feeding off her while keeping her alive until it can find more food. She fears that she has put the people in the station in danger. Her story matches Amis'. Back in Medlab Garibaldi, worried for Amis, asks Mariah to use her symbiosis with the creature to try to locate it.

Sheridan and Ivanova receive a partial signal from Garibaldi, who seems to have found the intruder. Armed with heavy weapons they go to the location and find two wounded security men being taken care of by Mariah and Dr. Franklin. Garibaldi is still trying to find Amis. Sheridan, Ivanova and their security detail split trying to locate them. In the meantime Garibaldi finds Amis suspended in mid-air by an invisible force. He shoots at it and the energy blast outlines something big, about three times the size of a man. It drops Amis and he and Garibaldi retreat, but Garibaldi's shots only slow the intruder down. Sheridan appears and his bigger weapon seems to be more effective, but still not enough to kill the creature. The intruder, who remains invisible until hit by energy blasts, retreats and seems to be cornered. Sheridan calls for Ivanova and the rest of the security detail to cover the exits and wait for the creature to reveal its location, but Amis claims that the creature is too intelligent and patient to be trapped that way and that they need the proper bait. He runs into the open, daring the creature to finish him off, until it attacks him. Once located, the continuous blasts of energy from the whole team reveal a large humanoid being, with horns on the head and a muzzle-like mouth that falls to its knees and finally disintegrates. Amis and Mariah will be able to find peace at last.

Amis sleeps calmly in Medlab. Dr. Franklin asks Mariah to stay with him in Babylon 5, but she replies that she needs time to adjust and wishes to see Earth again before she decides what to do. Ivanova finishes reviewing the Copernicus' logs and they all back Mariah's story up, except that after the creature came on board, the Copernicus changed its course and headed for the Rim, to the exact location that G'Kar already mentioned as the home of an ancient enemy: Z'ha'dum. If the Copernicus had not been an exploration vessel programmed to home on any radio signals and to answer them, it would have probably bypassed the station unnoticed.

G'Kar lights the candles in his quarters and reverently looks at the Book of G'Quan. A demonic figure, drawn in black ink centuries ago, appears prominently on the page. It is the representation of a creature just like the one that was killed.