He is a resident of the Tower, and appears during the main story quest Awakening. Mark needs to be rescued from the thirteenth floor after travelling there to visit his infected brother. However, he is injured and Kyle Crane is forced to kill his brother in order to rescue him. Crane must then craft a medkit for Mark until Doctor Lena arrives, escorted by Timur.
He is admitted to the sick bay on the eighteenth floor, but is not seen following the outbreak during Pact With Rais.