After Carol accidentally kills Gordon, a new addition to the Tuscon Crew, she and Tandy try to find a way to ease themselves back into the group; Carol fakes Tandy's death.
Phil and Todd rejuvenate their old friendship from Tuscon after doing time together; Phil and Phil 2's growing tension between each other over Carol reaches its tipping point.
When Erica claims she's pregnant to Phil 2 right before he is about to leave Malibu, he has to choose between his unborn child or a higher chance of survival by himself.
Along with most human life, the virus wiped out normal traditions and holidays. As Christmas approaches, Carol spearheads a "Secret Santa" gift exchange to spread some festive cheer.
Phil is diagnosed with appendicitis. Someone in the group has to step up to execute the surgery. Melissa has to deal with Todd's refusal of her proposal. Mike makes a decision about returning to earth.
Todd feels left out, as Tandy warms to having his little brother back on Earth. Meanwhile, Mike learns more about Erica than the group has ever uncovered about her.