The United Rebel Front was dealt a series of blows in 2530 when the SPARTAN-IIs sabotaged a number of their operations and destroyed their plans. This attracted the attention of Graves, who began to target the Spartans directly. In May 2531, he planned an elaborate ambush for them at Camp New Hope using several FENRIS Nuclear Warheads and an Antigravity plate. During the course of the ambush, he underestimated the Spartans, and was killed while trying to spring the trap after an Asteroidea Anti-Personnel Mine thrown by Kurt-051 exploded and sent a piece of shrapnel into his skull. John-117 described the loss of Graves as "unfortunate," as he held the secrets that ONI would have desperately wanted to get their hands on as well as knowledge of how far the Rebels had penetrated within the UNSC.