"Equilibrium" is the seventh aired episode of seaQuest 2032`s third season and eighth produced overall. It was originally shown on November 15, 1995.
Upon discovering a viral outbreak caused by a rescue mission mounted by the original seaQuest over a decade earlier, Lucas develops a method to counteract the agent. However, when Captain Bridger arrives on the scene and proposes to let the pathogen naturally break down, seaQuest soon finds itself locked in mortal combat with its former captain.
Upon discovering evidence that microbes have destroyed marine life in an area where the original seaQuest conducted a rescue mission twelve years earlier, Captain Nathan Bridger approaches his former ship with a convoy and holds them at bay.
Coming back aboard the ship, Bridger reunites with his old crew, but, is shocked to find that Lucas has enlisted in the U.E.O. navy, as he never believed him to be a career soldier. In a conference with Secretary General McGath, Bridger believes the best way to fight the microbe contamination is to let it naturally burn itself out, but, Lucas disagrees, claiming that the situation requires a more immediate response. Having developed an antigen, McGath orders Lucas to release it into the ecosystem.
Bridger refuses to back down from his position and returns to his ship. As seaQuest tries to maneuver past his fleet, Bridger orders his ships to block them. With no other choice, Captain Hudson fires three EMP torpedoes at Bridger's fleet, disabling two of the ships, but leaving his unaffected. Bridger, having designed seaQuest, uses his advanced knowledge of the ship to tap into one of the WSKRS and use it to remotely drive the seaQuest away, disabling the ship's power systems in the process. When Hudson asks Lucas how well he knows seaQuest, Lucas replies "well enough", implying that Bridger beat Lucas in the game of wits.
However, Lucas scores back by re-enabling seaQuest`s power systems, allowing the ship to fire their lasers at Bridger's propellers, disabling him. With no opposition, Lucas releases his antigen which begins to cleanse the water. As he tries to tell Bridger over the vidlink that he should have trusted him, Bridger replies "I did" and closes the channel.
On the sea deck, Darwin notices Lucas to be unhappy. Lucas claims he's not sad, just frustrated that his relationship with Bridger has degenerated from what it once was. O'Neill joins Lucas as the two reflect about their time spent on seaQuest. Lucas believes Bridger has changed from the man he once knew and respected, but O'Neill maintains that Bridger is the same, it is they who have changed.
However, trouble soon begins to arise when seaQuest springs a leak in the engineering section. When Henderson and Dagwood investigate, they quickly become sick from the water. Lucas realizes that his antigen has mutated the microbe strain, causing it to attack other forms of like besides marine, including humans and seaQuest`s bioskin.
With the crew growing sick and seaQuest`s hull breaking down, Bridger attempts to find someway to combat the virus. He takes a shuttle and dives deep in an attempt to find something to help develop a cure. Meanwhile, Captain Hudson recommends to McGath that a gamma warhead be detonated at seaQuest`s location to prevent the virus from spreading any farther. With ten hours before detonation, Lucas takes a speeder and heads after Bridger.
He finds the captain at the bottom of a trench, infected. While the two still cannot agree on what the proper course of action would have been, Lucas tells Bridger he did what he thought was right, something that Bridger always tried to teach him. Bridger agrees and tells Lucas for the first time since their reunification that he's happy to see him. He also presents him with a sample of algae found in the trench that is resistant to the virus.
Lucas is able to use the algae to develop a cure, but not before McGath launches the missile at seaQuest. With no chance of self-destruction, Hudson takes a subfighter to destroy it. With seconds to spare, Hudson is able to slice the missile in two with the use of the subfighter's pulse lasers and save seaQuest from certain annihilation.
With Lucas' new cure working to save the lives of the crew and repair the ship's bioskin, Bridger admits that his original solution may not have been the best idea either. When Darwin asks Bridger if he intends to stay, Bridger says he can't, for he must continue his search for his son. Lucas maintains his belief that he will, while Bridger postulates that he'd like it if Lucas and his son could meet one day.
- Bridger makes reference to Lieutenant Brody being dead, even though he would reappear in "Brainlock", due to a conflict in the airing schedule.
- Bridger's shuttle is classified as a "DS9 shuttle", a reference to Star Trek: Deep Space Nine. "Equilibrium" was the name of a third season Deep Space Nine episode, as well.
- Captain Bridger: Attention seaQuest, this is Nathan Bridger. I'm not letting you go any further.
- Secretary General McGath: Come now, Nathan. We're all on the same side, here.
Captain Bridger: Not this time.
- Lieutenant O'Neill: Captain Bridger is not a hostile target. He was our commander and our friend and I'd like to go on record as saying that I think this action is a mistake.
Captain Hudson: Lieutenant, Nathan Bridger became a hostile target the moment he disabled this ship. Now, get back to your station!
- Lucas: Even Bridger's changed.
Lieutenant O'Neill: No. He's the same. We've changed.
- Captain Bridger: Under the circumstances, I'm glad to see you.
Lucas: I'm glad to see you, too.