“Exogenesis” is episode seven of season three of Babylon 5.
The episode opens with a shuttle, Dyson, arriving at the station. A man and a woman watch the arrival, and the man says that they are finally here.
In a bar the promotion of Lt. (j.g.) David Corwin to full Lieutenant the next day is being celebrated. Ivanova comments that Corwin hates being the centre of attention. Dr. Franklin says that it’s a typical fight or flight response. Garibaldi wants to know why everything comes down to biology with the doctor; Franklin replies that everything comes down to one of two things: biology or maths.
When Ivanova is asked why she didn’t invite Marcus she replies that she didn’t think it was appropriate. She feels the celebration is Earth Force only. It’s pointed out that more than a few civilians have been invited by the others, so what’s one more. Besides, Marcus is one of them now. Ivanova asks if he is; he doesn’t wear the badge or the wings. Sheridan agrees, saying that it’s better if Marcus keeps a low profile for now. His reasoning is probably different; the captain seems to be considering that it would be better to maintain public separation between them and the Rangers – even if most don’t even know who the Rangers are. Franklin hopes that tomorrow will be as quiet and ordinary as today. Never say stuff like that!
The man and the woman who watched the shuttle arrive are currently watching a man on the floor, who is apparently in pain. On his back is a strange, insectile creature. The creature is seemingly absorbed into the man’s body, and the wounds on his back where it was heal. Then the man dies. Another turns up and says they have to leave as security is coming. One of the others replies that they can’t just leave him, but the newcomer says they have no choice, they can’t afford to be captured.
In C&C, Sheridan asks Ivanova to come with him for a quiet word. She asks if there is a problem and the captain mentions Corwin. Now that Corwin has been promoted, he could get in their business, and he could be a problem. Sheridan tells Ivanova they need to know where Corwin stands; he could be useful but if he can’t be trusted he will need keeping out of the loop. The captain wants Ivanova to sound Corwin out.
In Downbelow, Marcus comes up to a sleeping old man in a trade area, and quotes Shakespeare in his ear. The man, Duncan, wakes up and tells Marcus that he’s a madman. Marcus tells Duncan he shouldn’t be asleep, he needs to watch his wares. Duncan replies that they aren’t worth buying, let alone stealing. Duncan coughs, sounding unwell, but when Marcus suggests he should go to the clinic, Duncan replies that he doesn’t like being poked by doctors.
Franklin is briefing the medical staff on a number of matters. Afterwards, he asks if there are any other matters and he’s told that a DOA came in last night. The man had no ID and no sign of injury or illness. One of the other doctors would like Franklin to take a look, to see if he can figure out what to put on the death certificate.
Marcus is having a meeting with his contacts. One of them tells him that they have been advised to go to a heightened state of alert and to pull back from Earth space, because things are a little weird back home. Also, Shadow vessels have been seen gathering, forming a border on the edge of Centauri space. Finally, the package Marcus is expecting has just left Mars and should arrive in about a week. Afterwards, Marcus asks his go-between what happened to his previous go-between, Samuel. Samuel apparently has more important things to do. Marcus wants to go and speak to him.
Dr. Franklin is conducting the autopsy of the DOA, which is the man who had the insectoid creature on his back. Franklin can find no signs of what killed him. He has fingernail marks in his palms, suggesting heightened stress or fear at the time of death. The computer finds a neurological anomaly on the scan – there appears to be something wrapped around the man’s spine.
Marcus goes to see Samuel (Eric Steinberg). He is the man who warned the others about security coming at the beginning, and they appear to be there as well. Samuel tells Marcus that he can’t work with him anymore, as he has other things to do now. Samuel seems a little off; as Marcus leaves, he thinks so as well. As Franklin is performing his autopsy, he pulls a clear, wormlike thing from the man’s spine. Which moves. Samuel and the others are gathered about Duncan who is on the floor with another one of those creatures on his back. Franklin has determined that the creature, whatever it is, can exist in any lifeform, but doesn’t confirm to any known parasite.
Marcus speaks to Garibaldi about what is happening Downbelow, and how people are acting strangely. To the point where the chief asks Marcus if he ever shuts up. Marcus says no, not until he gets what he wants. Unless quiet meditation would work. Garibaldi replies that Ivanova was right – Marcus is a pain in the ass. Garibaldi isn’t going to look into things in Downbelow, because no laws have been broken. He tells Marcus that what he needs is a doctor. So Marcus goes and finds Franklin and tells the doctor that Garibaldi told him to see Franklin. Marcus… manipulates what was said a bit. Nothing is exactly untrue; just very misleading.
Marcus does convince Franklin to come with him so they head for Duncan’s quarters. Franklin can open them and does, and Marcus goes in. Inside is a hole in one of the bulkheads, with some sort of webbing in it. The two go through and find a man on the floor, who looks to be being infested by one of those insectoid creatures. Before Franklin can call security, more people – with guns – appear around them and capture the pair. Franklin says to Marcus that the creatures could take over the whole station without anyone knowing. Marcus asks why go for lurkers then; they have no strategic value, no authority and are not in a position to take over the station. Duncan, who is alive, doesn’t seem unhappy either. Is he being manipulated by his parasite? Marcus also things this is an excellent time to talk about Ivanova.
Ivanova herself speaks to Corwin as the captain requested. She says that, now he’s been promoted, they should get to know each other better. Corwin suggests breakfast at the mess hall; Ivanova tells him to come to her quarters for coffee instead. Corwin looks a bit stunned; Ivanova clearly didn’t realise how that sounded. So Corwin buys flowers to take with him. Which lead to another misunderstanding later.