General Abbot makes an example out of Gus. Dr. Singh obsesses over his research ahead of an important presentation. Becky crosses paths with a frenemy.

As polar night looms, Gus and his crew arrive at the outpost — but they're not alone. To find Birdie and the cave, they must brave several obstacles.

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.