Mark was one of Dale Collins' friends and was first seen in the house where Ricky Howard was delivering pizza. Moments later, Mark watched as Dale attacked Ricky outside and threw his keys down into the sewers.
During a confrontation with Ricky, who knocked Dale, Mark and Nick into the pool, a Xenomorph attacked. Everyone climbed out of the pool except Mark, who was impaled through the face by the Xenomorph with its inner jaw.
His body was later dissolved inside the pool by Wolf with Dissolving Liquid, along with those of Nick and the Xenomorph that killed them.