Kate Spencer is the head prosecutor in Los Angeles. Her latest case seems like an open and shut case. Copperhead has murdered and eaten 15 people in his latest rampage. Even though the whole attack was caught on video, Copperhead escapes the death penalty by found not guilty by reason of genetic anomaly.
Copperhead later escapes his prison transport, kills the two guards driving him, eating most of them before escaping into the sewer. Meanwhile back at her office Kate overhears the escape over the police radio. She steals her partners ID and breaks into an evidence locker and steals a staff and armor.
Kate, now donning a protective suit and a Manhunter staff, tracks down Copperhead. She overpowers him and uses the staff to blow a hole in his head, killing the super-villain. Before she leaves the murder scene she leaves one word scrolled on the wall, MANHUNTER.
The next day, Shadow-Thief, learns that his friend Copperhead has been killed by Manhunter. He then teleports himself to L.A. where he breaks into the morgue and takes two of Copperheads teeth both as a reminder of his friend and a weapon to use against Manhunter.
Meanwhile, Kate spends the day with her son Ramsey Robinson. The day seems to be going well until a busboy, who later turns out to be Dylan Battles, drops a milkshake on Kate and forces her to take Ramsey back to her place. There while Kate is out of the room, Ramsey finds her Manhunter Staff and blows up the apartment.
Ramsey is taken to the hospital and goes into a comma. Later Kate's ex husband Peter Robinson shows up and blames Kate for what happened to Ramsey, not knowing what really happened. Kate leaves the hospital, where she dons her Manhunter costume.
Kate is soon attacked by Shadow Thief, who easily overpowers her, and leaves her for dead. Lucky the suit that Kate wears protects her and she is able to make it back to the hospital where she keeps watch of her sons room from across the street.
With her suit and her staff damaged she makes it her mission to find Dylan Battles. She confronts him and they make a deal. Dylan will help Kate make better equipment and Kate will not turn him over to his former employers.
Meanwhile, Firestorm is killed by Shadow-Thief. Kate, now equip with better equipment, designed to stop Shadow-Thief prepares to track him down and kill him like she did to Copperhead. But before she can implement her plan she is visited by Martian Manhunter, Hawkman, John Stewart and Vixen, who inform her, as the head prosecutor of LA, that the JLA is looking for Shadow-Thief in her district.
That night Kate, dresses up as Manhunter and tracks Shadow-Thief to a cemetery. There Shadow-Thief has used his powers to temporary animate Copperheads body and Kate is forced to destroy Copperhead again. She then uses her new equipment to stun Shadow-Thief, just as Hawkman and the other JLA member show up to knock Shadow-Thief unconscious.
Kate is able to escape the battle field unnoticed, and plans to kill Shadow-Thief by trying him in court and getting him the death penalty. Unknown to Kate, Martian Manhunter, senses her, but is not sure who she is, due to Daylan's, psychic dampeners.