Convinced that mutants pose a threat to humanity, Dr. Bolivar Trask develops the Sentinels, enormous robotic weapons that can detect a mutant gene and zero in on that person. In the 21st century, the Sentinels have evolved into highly efficient killing machines. With mutants now facing extinction, Wolverine volunteers to go back in time and rally the X-Men of the past to help change a pivotal moment in history and thereby save their future.
