San Lupo fights for survival against the virus; Ish realizes the answers to humanity's future may not be in his books and finds Joey's secret project.

Ish catches Charlie assaulting Evie. San Lupo must decide how to punish evil. But will Charlie and his people accept their judgement? The virus returns. Joey falls ill, and Ish feels humanity’s future hanging in the balance.

A drought hits San Lupo. A nomadic group led by Charlie, comes. They know how to find water and want to trade. Ish has his doubts, but chooses to accept help. They strike water. But a trade might not be enough for Charlie...

New residents move in, Jorge and Maurine, and a mysterious mute girl, Evie. More come, Molly, Jean, Ezra and little Raif. Ish doesn’t trust them, Emma invites them in. A bad storm slams San Lupo, but the worst is yet to come...

Ish finds a survivor, Emma. There's a spark. Is it real, or are they just the last two people on earth? Nature is unrelenting. Rats plague San Lupo. Ish dreams of rebuilding civilization, but can they even survive extinction?

Ish, a solitary young geologist, barely survives a snake bite. After a coma, he drives to the nearest town only to find dead bodies. He searches for survivors, from San Francisco to Las Vegas. There must be someone else left...