Forced underground by the next ice age, a struggling outpost of survivors must fight to preserve humanity against a threat even more savage than nature.

Viktor: You know you're screwed when even the rabbits won't fuck.
Graydon: Shit. Hey, c'mon, let's get outta here, huh?
Briggs: Hey, find a spine, boy.
Briggs: That is not how we do things. We give people a choice. It's theirs to make regardless of the outcome.
Mason: 'Til they come back. 'Til the food runs out.
Briggs: It's not a problem until it's a problem.
Sam: What do you want?
Feral Leader: More...
Sam: The world froze over a long time ago. So long ago that I can't remember the warmth of the sun. I heard stories growing up... How the planet grew hotter as our fuel was burned. How we made towers to work the weather. But the truth is... one day... it started to snow. And it never stopped.
Mason: [to Briggs] You know... You'd think for someone who served with you you're give them a little more respect.
Mason: Briggs is gone. I'm running things now.
Sam: When everyone's dead, huh? And you're king of the fucking castle, then what?
Mason: I'll still be running things.
Sam: There's no one here. We only knew that you were here because of the knocking.
Leland: Yeah, but I didn't knock.
Briggs: Not so much of a welcoming committee this time.
Leland: We triangulated the, the transmission. Sent a team to find the source. But... they never found it. But somebody found them. And followed them right back here...
[starts crying]
Sam: Is there anyone else? Is anyone else alive?
Leland: Define alive.
Sam: This isn't right!
Mason: This is survival!
[shoots Hal]
Mason: Nothing personal.
Mason: We need to take care of our own, Briggs.
Sam: Viktor! Fall back!
Viktor: No! No more running!
Sam: [to Mason] You're gonna need every bullet.
Mason: They're done, Briggs.
Briggs: They're sick. And we follow procedure.
Mason: They just put the whole colony at risk. We need to give them a test right now.
Briggs: We're gonna wait until I get back and see if they've done any better. Until then Kai's in charge.
Mason: You really think she can make the tough calls?
Briggs: That's really not your decision to make, is it?
Briggs: Are we clear?
Mason: Crystal.