Earl Angstrom and his son Harry were both S.H.I.E.L.D agents. Harry had a desk job monitoring Deathlok, and was tragically killed by Biohazard, who ate his brain in an attempt to learn more about Deathlok.
Investigations into Harry’s death revealed trace amounts of Cybertek biofluid, leading Earl to assume that Deathlok had killed his son. Earl led a team of Mandroids to apprehend him. Deathlok easily beat the Mandroids, but showed mercy and didn’t harm any of them. Earl realized that Deathlok wasn’t a killer, and soon discovered that Biohazard was the real culprit.
Earl teamed up with Deathlok, and the two took down Biohazard, first containing his satellite organism that had disguised itself as Billy Hansen. Earl and Deathlok than tracked Biohazard’s core form and managed to destroy it; Deathlok tearing out the mutant brain of John Kelly that powered Biohazard, and Earl burning the corpse. Having brought down Harry’s killer, Earl was able to come to peace with his death.