During 2197, the Brotherhood sent the Warrior and Grail squad to Buena Vista to disable or destroy a nuclear power reactor, as well as power nodes, to shut down a nearby robot repair station. Grail squad was at the front gate of the complex before all members the squad became KIA.
No direct business was ever made between the Warrior and Grail squad, even though the former have already seen initiate Percy and paladin Lancelot in Brotherhood bunkers. At the beginning of the mission in Buena Vista, the screen moves over to the Grail squad, which has apparently arrived on the scene before the Warrior's own squad. Paladin Lancelot gives tactical combat orders to his knights at the gate of the reactor complex.
However, as Lancelot and his knights attack, they are totally obliterated by the guarding turret post of the facility. The other member of the squad, initiate Percy, has somehow managed to get past the turrets, but was mortally wounded by the Scurry bots. In his dying words, his asked the Warrior to continue the battle and avenge him.