Sergeant Dennis Riley is a U.S. Marine Corp's Force Recon member that was sent to investigate the American research facility, Fort Stewart, located in Antarctica.
Expert in Special Forces operations and various weapons. A rebellious teenager, Dennis soon changed his ways after an accident robbed him of his parents. On joining the Marines, he was assigned to the RECON unit, specifically team "Red Light". It was during this time he met with Cindy Chen, and along with a group of fellow marines that included his best friend and Cindy's boyfriend, Andrew - Dennis took part in several Special Forces missions. Tragically, Andrew was killed during one such operation in Cambodia. Blaming Dennis for what happened, Cindy sought to quell her grief by taking a position at Fort Stewart, a top secret government facility in the Southwest Antarctic. A year on from this event, Cindy is still holed up at the outpost, and Dennis's attempts to contact her have been unsuccessful.
On Christmas Eve 2005, Dennis' team was sent to Fort Stewart after receving a distress signal. However, the plane crashes after two engines were destroyed and the team was seperated. Dennis lands at the rear enterance along with teammate Roger Grigman. The two marines enter the facility through a ventilation shaft and Dennis recons the underground tunnel.
Upon entering Tunnel Area A to turn the power back on, Dennis comes in contact with Hydras, or Bugs. After returning to the drawbridge, Dennis was unfortunate to witness Roger get attacked and transformed by a few Hydras.