The ancient Kroll's awakening and rampage, created by the methane refinery's environmental destruction, becoming a destructive force threatening both colonists and Swampies

The Doctor and Romana’s sabotaged canoe is discovered on a reed bed where Swampie leader Ranquin and his warriors lie in wait. Rohm-Dutt’s explosive trap detonates on a gunrunner’s weapon …

Fenner and Dugeen surveil Kroll’s movement toward the refinery, their calm professionalism shattered when a tentacle breaches the entrance. The sudden monster attack escalates the crisis, confirming Kroll’s hostility beyond …