Crichton, now aboard a dying leviathan named Elac, encounters an alien named Sikozu who aids him in stopping the Grudeks who are intent on obtaining toubray (Leviathan neural cluster tissue).

SG-1 faces two potential disasters light years apart as an energy build-up in the Stargate threatens to destroy Earth and another world. Teal'c returns home to find out that his wife is dead, his son is estranged, and his planet is under attack.

Harry Harper starts work at Holby taking over for Max after he resigned as Lara becomes concerned that a police officer may have raped his own wife.