Set in the near future, the game follows Hayden Tenno (voiced by
Michael Rosenbaum of
Smallville) as a CIA operative on assignment in a fictional
Soviet-bloc country. Hayden suffers from congenital analgia, a disease that prevents him from feeling pain. While on assignment, Hayden is exposed to a mysterious biological compound that causes his right arm to acquire the ability to spontaneously grow a three-bladed throwable weapon called a glaive. As part of his body, the glaive mutation is also used to generate light, and is remotely controlled by the player. On his travels, Hayden encounters others affected by the compound; however, the pain involved in the mutation process drives its victims mad. Hayden's congenital analgia inadvertently protects him from this aspect of the mutation.