Videos: Gigi Edgley

The crew returns to Moya - in orbit around modern-day Earth - to find Jack and a contingent of Earth dignitaries waiting for them. The aliens are introduced to an amazed and apprehensive public, but soon find life in the public eye difficult. As Crichton tries to readjust to life on Earth, his relationships become strained, especially with Aeryn. Meanwhile, a monstrous assassin sent by Grayza hunts for Crichton, and will stop at nothing to accomplish its mission.

Moya's crew tracks Aeryn to a Scarran Border Station, where the freighter she is imprisoned upon is about to leave for Katratzi, a Scarran base. To keep the ship docked and under quarantine, Noranti gives Rygel a deadly, contagious disease. Though this gives the crew time to come up with a plan to rescue Aeryn, they do not figure on the cunning and ruthlessness of Aeryn's Scarran captor, Jenek.

Crichton, Chiana and Rygel are reunited with D'Argo and Jool at an archaeological site run by Jool's people, the Interions. The purpose of the dig is to find a missing probe that might reverse the planet's dangerous atmospheric conditions. Peacekeepers led by Grayza land and capture the crew, and Crichton finds himself unable to fight back, mysteriously compelled to do Grayza's bidding.

The crew lands on a planet divided by generations of clan war. After experiencing strange hallucinations, Aeryn is subliminally coerced into assassinating a clan leader. When Crichton also starts having hallucinations, they must uncover the planet's political machinations in order to prevent more killings.

D'Argo and Sikozu come up with a plan to crash Elack onto the Peacekeeper pursuit craft, facilitating their escape. Crichton is forced to consort further with Grayza to ensure success. When the plan goes awry, the crew begins a search for the probe that will reverse the planet's deadly atmospheric conditions, but a most unexpected enemy stops them in their tracks.

Moya's crew travels to Katratzi, a Scarran base where Scorpius is being tortured for wormhole information. The base is home to both Kalish and Charrid forces - underlings for the Scarrans. The crew plans to incite a confrontation between these two contingents, hoping this diversion will allow them to free Scorpius, and prevent wormhole knowledge from falling into Scarran hands.

After thwarting Crichton's escape plan, Scorpius denies that he's a Scarran spy, and demands Crichton's help to destroy a cavern of vital Scarran flora - claiming it will also provide them with a better means of escape. And while Rygel and Noranti fight an evil Stark, Sikozu must reveal her true colors if they are all to survive.

The crew board Scorpius' Command Carrier under the falsehood that Crichton is there to master wormhole technology. The ex-Peacekeepers Aeryn and Crais are forced to confront their past lives, and D'Argo, Rygel, Chiana, and Jool encounter unhidden hostility from all sides. Talyn is also implicated, brought on board for a cognitive replacement. While Crichton searches for a way to sabotage the Carrier, he is being watched by Scorpius, who is ready to exact deadly retribution if Crichton does not cooperate.

On the Command Carrier, Crichton is making incredible breakthroughs in his wormhole research, accessing information previously locked away. His crewmates are not so sure about the success of the plan, and are debating whether to leave or stay. Crais also has his own interests at heart, and when he is denied access to Talyn by the Peackeepers, he realizes he needs a bargaining chip. He goes to Scorpius and reveals Crichton's true intentions: to sabotage the wormhole research and destroy the Carrier. The plan blown, Moya's crew is immediately arrested, and it seems all is lost.

While searching for a planet to heal the dying Zhaan, Moya collides and fuses with a small spacecraft, seriously injuring Moya and trapping both ships in a series of looping wormholes. Crichton and the captain of the other ship, Neeyala, soon realize that one of the ships must be sacrificed if any of them are to survive.

An Ancient - again taking the form of Crichton's father Jack - appears on Talyn and accuses Crichton of sharing wormhole stabilising technology with the Charrids, a vicious race who have formed an alliance with the Scarrans. Crichton realizes that Furlow, the mechanic from Dam-Ba-Da depot who once repaired Crichton's module and had a mercenary interest in wormhole technology, is the real guilty party. With a Scarran Dreadnought heading towards Dam-Ba-Da to collect Furlow's data, Jack must unlock the wormhole technology in Crichton's brain in order to build the ultimate weapon - but must first confront the evil Scorpius Clone in Crichton's mind.

After disposing of the Scorpius Clone, the Ancient 'Jack' unlocks the secrets to wormhole technology in Crichton's mind allowing them to build a Displacement Engine, the 'ultimate weapon' that will allow them to destroy the Scarran Dreadnought before it escapes with Furlow's data. Seeing the value of the weapon, Furlow kills Jack and takes off with it. In the ensuing chase, Crichton is fatally exposed to the highly reactive Partanium that fuels the engine. With nothing left to lose, Crichton volunteers to launch the weapon at the Dreadnought, experiencing first hand the terrifying power of the wormhole technology.

Hoping to preserve their own ship at Moya's expense, Neeyala's crew has been sabotaging Moya and hastening her disintegration. Crichton and the crew must battle not only the saboteurs but also a mysterious and deadly alien serpent. As the situation worsens, the only possibility of saving Moya requires that one of her crew make the ultimate sacrifice.

Crichton comes across the same conditions that created the wormhole that sent him to Moya. He and Aeryn leave Moya in his module in an attempt to create another wormhole and return home. Although a wormhole forms, it is unstable and damages the module. Crichton and Aeryn are forced to make an emergency landing on a planet to make repairs. There, they encounter a holographic message sent by Crais, offering rewards for: D'Argo, Zhaan and Rygel.

Moya responds to a distress call from another pregnant Leviathan. The crew learns, upon arrival at the planet from which the call originated, that they've been deceived. The call actually came from a group of exiled Delvians (Zhaan's people) who want to learn -- forcibly if need be -- how Zhaan overcame the madness caused by giving in to her anger.