At an unknown date Rachel was born as the daughter of Jean Grey and Scott Summers and she led a happy among the X-Men in Xavier’s mansion although the public view of mutants had taken a turn to the worse when the Brotherhood publicly assassinated Senator Robert Kelly. Now other politicians picked up his ideas and had now the support of most citizens. The Sentinels program was restarted and the first anti-mutant president was elected.
Rachel was still a little girl, when her mother died in a nuclear explosion device near Pittsburgh caused by Mastermind. The government used this disaster to finally outlaw mutantkind. (flashbacks Excalibur #52, Uncanny X-Men #141)
For quite some time the X-Men, whose identities were secret, could maintain their cover of running a school for gifted youngsters, but one day the military found out and attacked right as Nightcrawler and Amanda Sefton were escorting Illyana to her school bus. All three are shot and Xavier dies when the mansion is destroyed by missiles. (memory in New Mutants #18)
The troops searched the debris and found one sole survivor in the teenage Rachel. She was taken to the labs and for long months had to endure painful tests, drugs and
attempts to hypnotize and brainwash her. Finally she gave in and became the prototype of a so called hound. Ahab, the leading scientist, turned mutants into these mindless slaves, whose sole purpose it was to detect more mutants and lead the military to them. When not needed the hounds were held in pens. (flashbacks Excalibur 52, Uncanny X-Men #189)
In the meantime the Sentinels have concluded that the best way to protect humanity is by ruling it. Those mutants that aren’t killed or turned into hounds are transported by so-called Cattle Cars into concentration camps to await further genetic experimentation. (mentioned in Uncanny X-Men Annual #17, Excalibur #52)
With her inherited telepathy Rachel was one of the best hounds, but unnoticed by Ahab, Rachel stayed in a mindlock with each target when they were killed, and with each death she fueled her shame, grief and anger to the point where she was able to resist her programming and attack Ahab. Even though she was quickly defeated by the Sentinels, she had managed to scar Ahab’s face forever. In the following months Rachel was able to resist all attempts of re-programming her into a hound and finally she was sent to the containment camp, where she met the remaining X-Men (Franklin, Storm, Colossus, Kate Pryde). There Rachel learned that in the meantime most other super-beings (mutant or not) had either been killed or imprisoned. (flashback Excalibur #52)
Other members of the X-teams managed to avoid capture. Jubilee, Leech and Synch heard of the X-Men‘s incarceration but had to keep a low profile. Magneto asked their help to locate Logan, who had been left amnesiac after a telepathic attack by the Hellfire Club's Red Queen Psylocke. Jubes and Magneto found him, and had his mind restored by Emma Frost. Together they freed the Scarlet Witch from a catalysmic engine she was chained to. The Hellfire Club used her power to alter probabilities around the world. During the rescue attempt Magneto’s legs were shattered by falling debris during a fight with Shinobi Shaw, yet Logan pulled him out. Wanda dies in Magneto’s arms, he promises her to help the X-Men. (Wolverine : Days of Future Past #1-3)
Shortly afterwards Magneto too was imprisoned (possibly he let himself get arrested to establish a contact between Wolverine and the detained X-Men ?). In the camp the X-Men came up with a plan, they wanted to use Rachel’s mutant power of timely astral projection to alter the past. Logan, the only free X-Man, helped Kate Pryde to smuggle in components of a device that would negate the power-canceling collars.
As Kate got back to the camp, she claimed to be late from schedule (obviously she is forced to work somewhere and return to the camps at certain times) because of being attacked by mutant haters. She met up with Magneto, Storm, her husband Colossus, Franklin and Rachel and they secretly put together the jammer, that gave them free use of their powers. Once rid of the canceling collars, the plan went into it’s crucial phase.
Rachel used her powers on Kate to exchange her psyche with that of young Kitty Pryde in the past, shortly before Senator Kelly’s assassination to prevent this initial event. Kate was chosen for this plan, since young Kitty was the only one, whose psychic defenses were not yet properly trained.
With the main plan working, the future X-Men tried to use their returned powers to their advantage. With Magneto remaining behind to cover their escape, the others broke out of the Camp and Colossus carried Kate’s unconscious body. They met with Wolverine and plan a suicide run against the Sentinels headquarter in the Baxter Building. For them it did no longer matter if they are killed, since none of this will ever have happened if Kate succeeds in the past. They used the subway tunnels to get close to their destination, but without warning the tunnels were ripped open and Franklin was killed by a blast before anyone can react. The X-Men fought their way through and reached the Baxter Building. Rachel remained behind to protect Kate’s body while Storm, Wolverine and Colossus entered the building. Inside however they were outnumbered by the giant robots who expected the attack. Rachel telepathically felt the X-Men dying one by one.
(As Kate arrived in the present it took her some time to convince the team of her cause, since they at first believe it to be a fairy tale. Yet Logan’s instincts told him that she moved and smelled different – like a grown woman instead of a teenagers. The X-Men traveled to Washington and witnessed as Kelly’s hearing was interrupted by Mystique’s Brotherhood. The two teams engaged each other in a fight; in the confusion Kate tried to keep track of the Senator and was able to safe him from being shot by Destiny. With her goal achieved, the time-displaced consciousnesses switch back.) (all from Uncanny X-Men #141-142)
Even though Kate and the X-Men had succeeded in the past, ...
Even though Kate and the X-Men had succeeded in the past, the future was left unchanged. In a safe hideout Rachel projected her astral self into the past to investigate, why they had failed. Floating over New York she discovered that by accident she had sent Kate cross-time into another reality’s past. As she prepared to return to the future she attracted the attention of the Phoenix Force, who was just passing by. At first mistaking her for Jean, it soon discovered that this was a the future daughter of Jean, with a similar psychic resonance.
Amazed by this timely anomaly the Force probed deeper and found out about the life of pain and misery that Rachel had led, yet she had never given up. Impressed by another such passionate creature, it decided to follow Rachel into her timeline.
Back in the future Rachel passed out from the strain of the journey and the Force revealed itself to Kate. She herself had nothing left to live for, but she asked the Force to give Rachel the chance for a fresh start. The next day Rachel and Kate disguise themselves as Colonel Carol Danvers and a hound and gain access to the facilities of Project Nimrod, where a new Super Sentinel was build. It was a suicide mission, once inside they planted a nuclear bomb, but shortly before the explosion went off, Kate said the codeword ”Dark Phoenix” which was the sign for the Force to supercharge Rachel’s power to send her back in time - physically. Rachel was unaware that she hosted the Force’s essence and her memory was suppressed by it; these conditions were part of the deal and Kate had wanted to give Rachel a new life, without the ghosts of her past haunting her. The prototype of the New Nimrod Sentinels picked up the frequency and followed Rachel into the present. (flashback Excalibur #52, #66, memory Uncanny X-Men #192)
(Rachel arrives in the main Marvel Universe in New Mutants #18 and Uncanny #184. Eventually she joins the X-Men and later becomes a founding member of Excalibur. For the most part her memory remains scrambled, though sometimes she catches a few glimpses of her former life. The untested Nimrod Sentinel who followed Rachel, first appeared in the present in Uncanny X-Men #194. The X-Men fought it a few times, but in the end it merged with the Mastermold and was sucked into the Siege Perilous.)
After the explosion, only the near dead body of Kate was found. She was examined and diagnosed of dying of radioactive poisoning from the bomb. Unfortunately a video camera had recorded the minutes before the explosion and on the tape Rachel was seen being sucked into a time-hole and the new Nimrod Sentinel following her. Ahab used the Sentinel technology to try to scan Kate Pryde for residue of the time-anomaly that caused Rachel to disappear. Suddenly the probing interfered with Kate's phasing power’s side-effect of disrupting electricity, right as the Sentinel found the right timewave frequency. Suddenly both the probing Sentinel and his captive are sucked into a similar time-hole. (Excalibur #66)
(Kate and the robot merged into Widget and landed straight into Excalibur 1 scrambled and without means of real communication. Over time Widget would evolve.)
Some years later in the main Marvel Universe, all of a sudden an adult Franklin Richards appeared in New York. He was the mental self of the Franklin that died in Rachel’s timeline, who in the instant of his death wished himself to a time when he felt safe. This Franklin was tracked and followed by Ahab. It took the combined might of X-Factor, the Fantastic Four, the X-Men, the New Mutants and Rachel to defeat the future mutants hunter, who briefly turned Cyclops and Invisible Woman into his hounds too. He returned to the future, but now he knew that Rachel was still alive, like he had always suspected. After he left, Franklin, who subconsciously was feeding of Rachel’s energy, had to accept his death or otherwise he would have permanently injured Rachel and young Franklin. (X-Factor Annual #5, Uncanny X-Men Annual #14)
Much later after Rachel‘s memory was restored, she decided to go back to the future timeline, since she felt responsible and wanted to deal with Ahab’s crimes. Of course her teammates opted to help her and they made a time-jump to a point two years after Rachel had escaped. The appearance of Widget in the same examination chamber two years after Kate vanished alerted Ahab to a possible return of Rachel. Yet together with a team of future super-beings (Grace, Killpower, Tangerine, Dark Angel, Arthur), Excalibur managed to change the directives of the Sentinels of the era to preserve all life, thereby ending the genocide that had prevailed for years; only Ahab escaped. (Excalibur #66-67)