Minx tries to talk Henry into playing one more game with Drill; Claire and Wes race to stop Sean from causing a deadly incident.
The aliens keep Ryan in isolation on the mothership so Anna can experiment on his baby; Chad wants to fight with the Fifth Column; Erica seeks out a scientist who can explain Red Sky.
A homeless woman's surprising connection to the crossing provides answers about what really happened at the threshold; Naomi's growing influence at the camp leads to a shocking confrontation.