Previously, on Farscape:

On the planet Dambada, John Crichton has been in a battle for possession of his body with the neural clone. Aeryn prepares to shoot Crichton in the mistaken belief that it has usurped John's brain. The Ancient they call "Jack" stops her. "Harvey" dies, and Crichton finally has his mind to himself.

To combat the approaching Scarran Dreadnought, Jack unlocks John's wormhole knowledge, and they begin work on the Displacement Engine.

Back on Talyn, Stark and the still-blind Crais have to contend with a Scarran who has managed to board the ship and is determined to take control. Stark and Crais manage to trick the Scarran and Talyn shoots him.

On Dambada, as they work on the device, the wormhole knowledge slowly filters through John's mind. Finally, with only one stage to complete, John and Aeryn exit the area while Jack installs the partanium - a highly radioactive substance that powers the device. While they're gone, Furlow shoots and kills Jack, and steals the engine.

Planning to sell the Displacement Engine to the Scarrans, Furlow escapes in a sand buggy, but is pursued by Aeryn and John. Aeryn has to jump off to battle a Charrid pursuer, and when John finally catches up with Furlow she is being interrogated by the Charrids. John uses the opportunity and the distraction to retrieve his Displacement Engine, and rejoins Aeryn. With nothing to show the Charrids, Furlow is dragged away by them to 'explain' her failure.

Aeryn destroys the rest of Furlow's Complex, hopefully so no chance of any trace that could lead future seekers to wormhole technology remains. The wounded Rygel boards Talyn's transport pod and leaves the planet, waiting out of range to rejoin Talyn.

Insisting she accompany him, Aeryn joins John in his module, and they fly toward the Scarran Dreadnought.

Releasing the weapon, he demonstrates the terrifying power of wormhole technology. The Dreadnought is destroyed, and following brief farewells, John and Aeryn leave for Earth…