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

Elac arrives at the planet where D'Argo, Jool and Old Woman are investigating the ruins of an ancient civilization.

Crichton must find the third probe to end the magnetic summer, while avoiding Grayza and Oo-Nii.