Back mouth

Macready shook the cobwebs out of his brain and scrambled across the floor to grab up the torch. He raised it, aimed and fired.

Nothing happened. The blow against the wall had damaged it. Frustrated, he got behind Palmer and began hammering on the shifting, changing skull.

The shirt on Palmer's back erupted in the pilot's face, exposing not an arm this time but the beginnings of a second set of jaws. Something like a tentacle lunged out of the widening maw, reaching for Macready. He managed to dodge it, throwing himself backward. He bumped into the overloaded table and howled as the Bunsen burner scorched one hand.