Sometime in 1997
, six heroes formed Earth-9
's first real heroic superteam, the Secret Six
, in response to a major threat posed by Doctor Aquadus, a living ocean who also called himself "Aquaman". Plastic Man
had "recruited"/kidnapped Spectre
for a Nightwing
operation, Manhunter was looking for Dr. Aquadus who had worked at the chemical labs at Svitavy and inflicted horrors on her nation, Joker
and in another location Atom
found out about Sea Devils washing ashore, and so all met in the undersea labs of Dr. Aquadus. They faced many would be super villains aside from Dr. Aquadus, being Warlord, Damage, and the Eclipsos (a positive and negative energy woman duet). The end result was they stopped group from succeeding with Dr. Aquadus' plan of destroying the moon. Concluding their mission, Atom was impressed by how well the group worked together, and asked that they form a team.
They came from all walks of life, from high in public eye to part of the secret organization of Nightwing. So they decided to form a secret bond, and called themselves the "Secret Six".
Missions after that were either done as a group with all members in the mission or with select members.
The next recorded mission had Spectre, Plastic Man , and Flash. Nightwing was planning on capturing the Flash, and also Plastic Man who was making his intentions of leaving Nightwing known. Spectre captured them as a Nightwing agent. Plastic Man and Flash were subjected to carefully made cages that were designed to nullify their powers. However, thanks to advance inside information from Spectre Plastic Man and Flash had switched places, so the cages were ineffective. In the end they together trashed the Nightwing headquarters and rescued Plastic Man's true human body from the Nightwing labs, and with that, safely ended the employment of Spectre and Plastic Man with Nightwing.
The Atom assisted Joker in a case in New Atlantis when she was in over her head with some local enforcement robots, and secretly helped her elude police capture. They were starting to look into civil disturbance in New Atlantis towards Metahumans when the EM pulse from the creation of the Ultra-Humanite disabled all power throughout the world. Atom was weakened and was captured by a metahuman hunter group known as the "Justice League of America" when Joker (all of them) came out to outwit the group and took Atom to safety.
The Secret Six was the first group to take a stand against the Ultra-Humanite in New Atlantis. While their fight with the mega powerful being did not do much to stop the creature, it did give later heroes a gauge on how powerful the creature truly was.
According to the memory of Halo at the Core The Superman led many heroes on a great crusade against the Ultra-Humanite that was both costly in lives and destruction to the planet. More than likely, the Secret Six was there with him to help in that great war.
Following the Ultra-Humanite the Earth was devastated once again when all the Earths were brought together in an Infinite Crisis. At which point the entire Secret Six along with the SuperMan and other heroes worked together to help save their world.
When the SuperMan imposed the Global Peace Decree - a set of laws enforced by him, which made him the ruler of the world the Secret Six assembled to oppose this removal of liberties. The Secret Six attacked the White House , and defeated a squad of Firestorm troopers, but were stopped by the SuperMan, who disabled Plastic Man and killed Joker . After this, in response to the Global Peace Decree, the team was forced to "officially" disband. More than likely however, since the Secret Six was a secret group to begin with, they probably continued to meet in secret.
For a while they searched for Mary Marvel/Joker that the Superman had taken prisoner. We know that Manhunter, Spectre, Plastic Man, Flash, and Atom managed to elude capture for nearly ten years. With one of the Jokers presumed dead, they knew of the whereabouts of Lori Lemaris, but speculation would say that they believed she was safer in the new era Indoctrination Program. As for the third Joker, Madame Christy Xanadu, either her situation was the same, or her identity and whereabouts were also kept secret. Speculation suggests that after loosing one Joker in a direct confrontation with the SuperMan, they took steps not to unnecessarily involve the other two Jokers. Or perhaps Madame Xanadu was able to help from hiding.
Instead, just like in the case of the Ultra-Humanite, the Secret Six realized they needed more firepower to confront the SuperMan, and joined forces with remaining members of Night Force, and gained the help of Sir William and the Green Lantern calling the larger merger of groups "The Outsiders". Unfortunately Green Lantern, separated from her lantern by the Infinite Crisis, she was powerless and continued to grow weaker physically by the year.
In a strange turn of events, the lantern activated from where it was being stored on New Earth, and pulled the Atom and Flash across a multi-universe rift. The ultimate result was, Atom managed to find the lantern, but was unable to activate the lantern to send him and the lantern back to return to the Green Lantern. Unfortunately for Atom, the native defenders of the other world managed to knock him out just prior to the lantern returning Atom to his own world, where he was finally, after nearly a decade of evasion, captured by the SuperMan.
The Flash remained on the other world for several months, had multiple adventures both recorded and unrecorded, finally helping the New Earth's Flash , who after saving his life led the Tangent Flash to the location of the lantern which was then stored at the Justice League of America headquarters. Fortune worked for the Outsider's favor when Flash returned accidentally with a new batch of heroes from the other world that would become instrumental in their cause.
Eventually the Outsiders were able to save the Atom and other heroes who would be captured in the early attempts of his rescue. Regrettably Manhunter would loose her life in the process at the hands of Powergirl.
Before The Outsiders final push to confront the SuperMan, Lori Lemaris,
was brought back into the group. Hearing of the death of Manhunter and still saddened by the loss of Mary Marvel
, opted not to resume wearing the Joker outfit but took the mantle of the Manhunter. Plastic Man was reformed magically by Sir William and Hex and was then able to use his form shifting abilities of his polymer body. In the final battle against the SuperMan on new Earth of the other world defenders and The Outsiders, five of the Secret Six members were present.