Crichton, who is now aboard a dying Leviathan named Elack, works on his theories of wormhole physics. But when a female alien named Sikozu lands on the ship, she is followed by a squad of Grudek mercenaries who want to harvest the Leviathan's neural cluster tissue. Crichton struggles to save his new home but gets some welcome help when two old friends rejoin him.

When D'Argo and Sikozu come up with a plan to crash Elack (the dying Leviathan) into the Peacekeeper pursuit craft, Crichton is forced to get closer with Grayza to ensure the success of the plan. But when the plan goes wrong Crichton and the rest of the crew are forced to go looking for the third probe to end the magnetic summer forever.