Graham Directive Security is a mercenary organization which appears in the Predator comic series released in 2009 by Dark Horse Comics
The mercenary team was deployed to Africa to help defend against rebels. When they were there they fell under the scrutiny of a group of predators. The predators that hunted them were not typical hunting Yautja, but "Killers." Almost the entire team of mercanaries were killed by the Killers.
Thorpe: Thorpe was the leader of the Africa mission. He is a hardened individual who pays no respect to military ranks or authority. He had prior experiences with predators before the incident in Africa.