The Mark is a tactical first-person shooter where you have to prevent a large-scale terrorist threat. The terrorists received a nuclear warhead from the son of a Russian millionaire, and a launch vehicle from Iraq. Their destination is London, England. Two specialists were called in to stop this madness. For Steve Fletcher, an elite US Marine officer, it is also a personal vendetta — terrorists have kidnapped his sister. And for mercenary Austin Hawk, this is his life's mission.