Ruth and Adam suffer rapid advanced aging after exposure to gas from a lake polluted by Orkus, despot of a domed community of immortal elites who is also scheming to steal the ARK to generate power for his dying city.
During a devastating drought, Fagon and his Flies return and hijack the ARK in an attempt to secure a time capsule containing a cloud-seeding device. A primitive tribe that worships the time capsule has captured Ruth, Samuel and Adam.
The ARK crew unwittingly opens a Pandora's Box of pollution when they revive a 20th Century business tycoon determined to kick-start production of his trademark toxic chemical fertilizer.
The ARK encounters a community enslaved by a sentient super-computer housed in a black monolith. Samuel succumbs to the computer's control, jeopardizing Jonah's plan to deactivate it.
Samuel creates a robot that could prove useful when exploring a sector permeated by a strange gas, but Jonah is unwilling to allow Alpha-One to assist and orders him deactivated. Alphie has other ideas.
Red balloons bring word of an epidemic sweeping an isolated community, but its xenophobic leader is resistant to allowing the Ark to enter with a vaccine.
A band of orphans led by the thieving Fagon have found canisters of poison gas that they plan to use against the bullying War Lords. The Ark II crew must intervene to prevent mass murder.
When a tyrant hoards grain to create fuel while his people starve, a post-apocalyptic Robin Hood arises to right the wrong. The ARK arrives hoping to mitigate the mayhem and mediate a peaceful solution.
The Ark II comes upon a village that forbids machinery. Will they reconsider when a functional 20th-century battle tank could aid in the rescue of their leader's daughter, who was abducted by marauding scavengers?