Kate Spencer is a federal prosecutor who grows increasingly tired of seeing guilty criminals evade punishment. Copperhead, a supervillain on trial for multiple murders and cannibalism, avoids a death sentence and escapes from custody after killing two guards. An angry Kate takes matters into her own hands, stealing equipment from an evidence room and killing Copperhead. Calling herself Manhunter, Kate blackmails a former weapons manufacturer for numerous villains named Dylan Battles — who is in the Witness Protection Program — into building, maintaining and upgrading her armor, weapons and gadgets.