Slater served in the U.S. Marine corps before being recruited by the CIA. He subsequently became a mercenary to attain greater fees. His jobs included bodyguarding a Colombiandrug lord until the DEA moved in and Slater had to escape by killing more than eighteen DEA agents. His next job landed him in the employment of four terrorists who were killed by the blast of their own pipe bomb. (Most likely sabotaged by Slater who had learned that they were attempting to alter his salary.) Slater leapt over a fifteen foot ridge to escape FBI agents who had discovered that he was training a paramilitary group in Colorado.
Slater was later contacted by a mysterious "shadow agency" known only as Home Base. Home Base wanted Slater to capture Bruce Banner, who was on the run after the Hulk was implicated in the murder of a child, Ricky Myers. Slater refused at first after the organization requested he work with another mercenary, Sandra Verdugo for Slater arrogantly believed he could tackle any task given to him alone. The organization turned their offer into a challenge, urging Slater to accept the assignment. He and Sandra followed Bruce Banner to a desert cafe where Bruce was attempting to rendezvous with Doc Samson. There Verdugo drugged Bruce, and Doc Samson deliberately attacked Banner causing him to transform into the Hulk. Slater than killed Sandra for her plan's failure and because of his initial mistrust of her. Verdugo's drug caused Hulk to sleep walk into the woods. The Hulk entered a cabin where Sandra, miraculously still alive due to "H Section Programming"; soothed him causing him to return to original form. Slater entered the woods and killed two Home Base agents each carrying a component to a gun designed to sedate the Hulk. Armed with the "Hulk Gun", he charged into the cabin and shot Sandra Verdugo in an attempt to draw out the Hulk. Verdugo regenerated and activated C-4 explosives under the shack that killed Slater in the ensuing explosion.