The Sliding Ice Door Cuts Off Your Escape

You enter a cavernous circular room, the exterior wall of which is made of smooth thick ice. Flanking the central diameter of this room are two snowbanks that extend 10 feet and raise all the way up to your waist. Another one of those sliding ice doors is in the process of closing, and for a moment, you see three people behind it. You hear their muffled conversation: We better hurry, we can't let them get credit for this job. And another voice says, Don't sweat it, Ray. If they catch up to us, we'll just kill them too.