Rook-B312 was a SPARTAN-III Commando in the Beta company. Rook was very well mannered and had a good common sense. In training he would always train very hard and in turn, he became very skilled with many weapons. Although he could use most weapons very efficiently, he usually uses the M392 DMR and the M319 Individual Grenade Launcher. He prefers to be called Rook as it was the name he had gone by while he was in school.