With loved ones beside him, Gus goes on a treacherous journey into the cave to find a cure once and for all. Meanwhile, chaos breaks out at the outpost.
After a daring rescue, Gus meets an individual well-versed in hybrid history. Amid emotional reunions and eerie revelations, all roads lead to the cave.
Gus and his cohorts set out for Alaska to reconnect with Birdie, who’s working on a cure for the Sick. But first, they test their luck at an old casino.