After being kicked out of the Australian military for his behavior, Buck made his way to Rook Island, where he made his name as a gun for hire.
He purchased Keith Ramsay, and casually put him through physical torture at the least and repeated sexual abuse at the worst for his own entertainment. Later, Buck used Keith as a bargaining chip to force his friend Jason Brody, a highly skilled improviser, to find a legendary Chinese knife, which was also desired by Citra Talugmai.
Buck surreptitiously put a tracking device on Jason in order to follow his whereabouts, and sent him to recover the location of the knife from the ship of a treasure hunter who had been killed by Vaas Montenegro's pirates. However, Jason instead found an ancient, potentially magical compass, and triggered a security device which sank the ship before he found the knife's location in the ship's files.
The compass then lead Jason to two different sets of ancient ruins, where he found two additional pieces of the compass. Along the way, Buck made casual threats towards Keith that he may or may not have followed up on, and took obvious pleasure in forcing Jason, who hated his guts, to dance to his tune. When all three pieces were united, the compass finally lead Jason to the tomb of an ancient Chinese pirate named Lin Cong, who had the knife buried with him.
Retrieving the dagger and barely escaping with his life, Jason made his way to Buck's home, where he gave Buck the knife and found an abused Keith in the basement. However, Buck tried to renege on his deal with Jason, intending to trap both men in his basement as his personal sex slaves. Jason and Buck engaged in a knife fight, and much to Buck's dismay, it ended with Jason plunging the ancient knife Buck had so badly desired straight into his heart. After Buck's death, Jason brought Keith to the cave where his other friends were taking refuge from Rook Island, and brought the knife to Citra.