X-Factor Investigations is a detective agency run by Jamie Madrox. The agency was originally named XXX Investigations, but team members thought that it sounded too much like Madrox was investigating pornography. The new name is taken from the government-sponsored mutant supergroup that the three founders had previously served on.
The initial staff consisted of Madrox's best friend and special enforcer, Guido Carosella and former teammate Rahne Sinclair. Following the House of M, Madrox's newfound wealth from winning a Who Wants to be a Millionaire-style gameshow allowed him to recruit several of his former colleagues of the Paris branch of the now defunct X-Corporation. New members include Siryn, a powerless Rictor, M and Layla Miller, who has inserted herself into the group to keep them from discovering the truth behind the mutant Decimation. Recently, the team has come into conflict with rival agency Singularity Investigations, after they ordered Siryn beaten and left for dead. After meeting with Singularity CEO Damian Tryp, Madrox has asked Siryn to find out more about the Decimation from the heroes who might have been involved (by using her modulated voice to make them more suggestible). She learns from Spider-Man that the X-Men (who had denied any involvement), as well as Quicksilver were, in fact, central to the ending of the House of M and the subsequent Decimation. Little is known about Damian Tryp apart from that he runs Singularity Investigations, which is in direct competition with Madrox's X-Factor Investigations and his encounters with Madrox's team. He is also one of the few mutants that kept their superhuman powers after the M-Day, although it has been revealed that he might not be a mutant, but a genetic throwback to an earlier time, a "changeling", a predecessor to mutants who develops powers at birth. Tryp’s mutation enables him to live for a very long time, as evidenced by him being alive in the 12th-century Wales. He also is able to move through time in a similar fashion to Quicksilver, which enables him to bring together himself at three different times. Damian Tryp also seems to be involved in Jamie Madrox’s past. When Jamie was born, the doctor’s slap caused him to multiply into two identical babies, which was rather shocking to both his parents and the doctor. Professor Charles Xavier, a friend of the Madrox family, suggested that they move to Kansas to raise the boy in privacy with the possibility of the boy to be later taught at Professor X’s school for the gifted youngsters. However, when Madrox was still young, Tryp also makes an own offer to look after Jamie, claming that Jamie was also a "changeling" like him. Jamie's parents, however, refuse to give Jamie to Tryp, who proceeds to create a freak tornado that kills Jamie’s parents. The all out conflict between Tryp's Singularity Investigations and X-Factor Investigations began after the youngest version of Tryp badly beat Siryn (after shooting her in the neck with a dart that prevented her from using her powers) and left her for dead. Siryn, as part of her duties for X-Factor Investigations, was investigating the murder of the woman who died in Jack Vaughn’s penthouse under suspicious circumstances. Jack Vaughn (a movie star) claimed that the woman was killed by her sister, Gloria Santiago, who was upset about the relationship (claiming that Jack was “no good” for her sister), and that all he was trying to do was wrestle the gun away from her. The sister thus hired X-Factor Investigations to help her clear her name and bring Jack to justice. Singularity Investigations was representing Jack Vaughn with Tryp, Junior (i.e., the youngest version) as the defense counsel. Siryn and X-Factor Investigations managed to incriminate Vaughn and to thwart SI’s assassination attempt on Rictor. Tryp, Junior was so infuriated by this that he ambushed Siryn and beat her almost to death, leaving her to die in an alley. Madrox and Strong Guy give Tryp a very public warning as Tryp is jogging in the park. They tell Tryp that they know that it was him who hurt Siryn, and while they will not hurt him in broad daylight, he should watch his back. Tryp, Junior and Tryp, Senior make Madrox an offer to join their firm, and Madrox laughs in response.
Recently, Quicksilver has returned to Mutant Town, having gained the ability to restore other mutants' powers from the Terrigen Mists. X-Factor used this to confront the X-Men with their knowledge of the Decimation. As a result, X-Factor has taken a public stance in defiance of the Superhuman Registration Act. However, Rictor and M were registered by a duplicate of Madrox who is an agent of S.H.I.E.L.D., and Madrox, Strong Guy, and Wolfsbane are already registered because of their membership in the previous, government-sponsored X-Factor. The X-Men have decided not to interfere with Quicksilver as long as he stays in Mutant Town.
It has also been exposed that Tryp and his company have been working on a new version of the legacy virus. A former Singularity employee came to X-Factor Investigations and related that Tryp was attempting to restart the Legacy Virus, the plague that killed several mutants, including, briefly, Madrox himself. Strong Guy was sent to drive the man to safety but once they were alone, Strong Guy killed him and called Tryp to report. It was later revealed that Tryp had placed a hypnotic suggestion in Strong Guy’s head to turn him into a sleeper agent. According to the oldest version of Tryp (ancient), all of Singularity Investigations' efforts to create the Legacy Virus have been to prevent a possible future in which X-Factor manages to undo the Decimation, but as a result, humanity is wiped out by the re-powered mutants in a bloody conflict. As such, X-Factor Investigations' new goal is to undo Decimation, but also to prevent the conflict Tryp predicted. Due to one of Madrox's dupes blowing up the SI building, apparently killing Tryp, Junior and Tryp, Senior (i.e., the middle-aged version), only the ancient Tryp (the one who has been alive the longest and has seen the grim future) is still alive. After the destruction of Singularity Investigations, the present form of Damian Tryp (the elder/ancient) reveals to Layla that her very existence had foiled his plans — she is a force of chaos like he is. Tryp also reveals that when he comes into conflict with Layla, terrible events occur as a result. Following her encounter with Tryp, Layla appears genuinely shocked for the first time: the glass of milk she is pouring overflows, spilling onto the floor. After finding out about the foretold event, each member of the X-Factor Investigations receives a session with Doc Samson.
After The Civil War
After Madrox's experience with his S.H.I.E.L.D. dupe, a dupe he has forgotten about, Madrox went on a quest to gather his lost dupes and revealed an ability to absorb himself into dupes. This quest met an end when he found a dupe who had built his own family. Meanwhile Siryn and Monet bonded in France and rescued a child from a riot. X-Factor was then attacked by the X-Cell and almost defeated. The X-Cell's members believed the government to be responsible for their lost powers. All but Marrow and Callisto were repowered by Quicksilver and Rictor—a process that resulted in the death of their leader and Abyss, Fatale and Reaper fleeing into the brimstone dimension to fate unknown. When Layla Miller revealed what truly happened to Callisto and Marrow, Rictor used his powers to expel the Terrigen crystals from Quicksilver's body (except for one, which Quicksilver kept) at the cost of his powers.
Madrox, Rictor, and an accompanying Layla Miller were alerted to the Xavier Mansion by Emma Frost during the mutant baby conflict. Madrox and Layla were sent to Forge's headquarters to send two dupes into different alternate realities. Layla jumped in with one of the dupes at the last minute, claiming she had a part to play in their mission. Unfortunately, Forge informed Madrox that there was no way to retrieve Layla and his dupes, who received instructions to kill themselves once they received the information they needed to get reabsorbed into Madrox Prime. Layla and the Madrox-dupe have since landed in Bishop's future, captured and abused in mutant interment camps. Rictor was instructed to go undercover as a Purifer by pretending to shoot Rahne as she attacked the group's members. He has since gained information on their artillery until his cover was blown by Anole and the other New X-Men. Rahne later joined the mutant group X-Force to hunt down Cable using their hyper-keen senses. Siryn was called by the mutant named Peepers asking to help him out. When Siryn arrived on the scene, Peepers was eaten to the bone by Predator-X who was already on his way looking for the next mutant to kill. Strong Guy, Siryn, and M joined forces with the X-Men against the various groups trying to take control of the mutant baby.
Divided We Stand
After a confrontation with Jamie about her leaving, Rahne reveals that she has seen herself murder Jamie and Layla Madrox on their wedding night, and not wanting to kill Layla upon her return from the dystopian future, leaves the team and joins X-Force. Meanwhile, Rictor, while walking down a street, think he has seen Layla. After following the young girl, he finds a young prostitute who happens to appear around the same age. After some aggressive words with the young woman's pimp, he gets into a fight that leaves him wounded. After Guido joins in the fight, the men quickly disperse, and he walks with Rictor to the E.R. Elsewhere, Jamie is seen looking for a fight, and finds himself at a Purifier gathering. After shooting their leader with a tranquilizer, Jamie makes three copies of himself, and readies for a fight. Siryn reveals to a reverend that she is pregnant with Jamie's child; and later at a bar, reveals to Monet that she intends to give birth to the child. Meanwhile, Mutant Town is under the clutches of Arcade with Rictor as his prisoner, Valerie Cooper returns as a supporting character and X-Factor relocates to Detroit, Michigan.
Sometime after Messiah Complex, Darwin goes in search of Professor Xavier because he wants to help him. He encounters Longshot, who tries to lead him to the Professor by using his powers. Longshot, however is unsure if his powers have been working correctly and tests them out on a group of people which turn on Darwin and attack. After a brief fight, Darwin manages to get away and the crowd turn on Longshot. Darwin's father hires X-Factor to find his son, supposedly because he feels bad for walking out on him and his mother when he was younger. Madrox, Monet and Guido track down Darwin and Longshot but Longshot is attacked by Jazinda and She-Hulk who are trailing after him because he is really a Skrull. After a fight between the two groups, they both realize Longshot is a Skrull, capture and hand him over to Jazinda and She-Hulk and go their separate ways.
After Darwin is reunited with his father, only to be betrayed and sold out to by operatives of an organization known as the Karma Project, who are experimenting on living human beings. Meanwhile, the real Longshot shows up and he and Darwin join X-Factor. Valerie Cooper takes an interest in Siryn's child. During a confrontation when Siryn is leaving for the hospital because her water broke, Val is accidentally shot. While Val recovers, Siryn gives birth and finally acknowledges that her father is dead and is never coming back. She names her son Sean, after her father but when Madrox holds him, he absorbs Sean. Jamie Madrox leaves X-Factor Investigations in order to talk to his last remaining dupe, John Maddox. Explaining to John that dupes are unable to have babies, John reveals that he already knew this. However, Jamie threatens to kill himself, knocking out John. Before he pulls the trigger, an older Layla Miller returns to stop him. Jamie is transported to the future in the midst of the Summers Rebellion, where mutants rise up against Sentinel and human oppressors, which is led by Ruby Summers, the daughter of Cyclops and Emma Frost with her fathers' eye beams and Emma's organic mineral body, Layla, and a cyborg Cyclops, whose predicament is Jamie's fault. After Jamie kisses Layla (now an adult) out of happiness at seeing her, Cyclops wants Jamie to find out why some mutants are winking out off existence. The group visit an aging senile Doctor Doom, who says Layla told him in the past that he'd have to instruct Jamie and her on something in the future, and it is now. In the present, X-Factor and new members Longshot and Darwin are battling Cortex, an agent of the Summers Rebellion era government. Cortex briefly controls Shatterstar and M, using them to respectively make assassination attempts on Reverend John Maddox and an X-Factor client. Cortex grabs Longshot, trying to also control him, and realizes him and Shatterstar are connected, and when Cortex loses control over Monet, she attacks him and his hood falls back revealing that he is the second Jamie Madrox duplicate from Messiah Complex. The Madrox dupe is teleported to the future once more, where his technological parts are taken over by an elderly Doom. There he engages in combat with the future X-Men. Although he manages to kill Fitzroy, Ruby begs Layla to bring him back revealing that Layla has the ability to resurrect the dead however her powers restores them without a soul/consciences. The conflict reaches its peak when a massive Sentinel is about to destroy most of the mutants. Fitzroy absorbs Cortex's life energy and sends the massive sentinel in the past (where the sentinel crashes killing it's constructors parents thus completing a chain of events that started all of this). Madrox is teleported back in the past, Detroit where he meets up with the rest of X-Factor. Layla however goes further back where she meets up with her younger past self. After telling her all of this she downloads her knowledge into her past self's mind thus further completing the causality loop and granting her the knowledge she had to begin with.
The Invisible Woman Has Vanished!
While Siryn decides to leave the group, Madrox decides to move X-Factor Investigations back to New York City, where he believes the team should really be. In their first mission, the team is approached by Valeria and Franklin Richards, who ask for X-Factor's help to locate their mother: The Invisible Woman, who has vanished. The team go to the Baxter Building but are stonewalled by Reed Richards who dismisses Sue's disappearance. While Guido and Shatterstar cause a distraction by fighting the Thing, Longshot gathers clues from the Fantasticar and surmisses that Sue has been taken to Latveria. Meanwhile, Monet discovers that her father has been taken hostage and will only be released in exchange for Monet herself. Monet, Guido and the Thing storm Castle Doom after being transported there together with the rest of X-Factor by Shatterstar in order to save Sue. Meanwhile, Madrox, Darwin and Longshot discover a grave containing the real Reed Richards who has been trapped there. Reed reveals that the Reed X-Factor met was in fact a Doom from another reality who transferred his consciousness into the body of that Reed Richards. X-Factor find the real Doom and Layla inside the castle. Doom tells them that the other Doom had tried to combine forces with him but Doom knew he would betray him eventually so he decided to let the game play its course and took Sue to Latveria because he found the other Doom's plans for her "distasteful". Sue is freed, the other Doom is killed and X-Factor prepare to depart. Layla reveals that she's been staying with Doom in order to ensure that his future self would let them use his time-machine to return from the future and in exchange for that and being tutored in magic, Layla has been advising Doom. As the team is leaving, Lalya whispers something to Shatterstar and he stays behind with her in Latveria.