The story tells us about the character of Moira Mactaggert. She's a mutant with very special abilities. She can reincarnate herself and can remember every life she lives. She could walk and talk at a young age because she remembered how from a previous life.
After amassing so much knowledge of biology and chemistry she discovers a cure for the mutant X gene. The lab she was working was attacked by Mystique, Pyro and Destiny where Destiny discovers that time bends around Moira Mactaggert.
Pyro kills her Moira and she spends her next life researching humans and mutants and realizes that there is no equal future for them. Moira discovers that at least one side is going to come out on top. Moira helps establish the mutant safe space of faraway where she's killed yet again by Sentinels But not before witnessing the X-men's history unfold.
She realizes that every time the Sentinels come they always come from Trask. She kills Trask after enrolling in the military. When that failed she spent her eighth life with Magneto and helped him establish a mutant homeland.
She helps him take over America and create the House Of M. Every hero was called in to stop them and they killed Magneto and Moira was imprisoned. She died during a prison break. Her ninth life was spent with Apocalypse after she awakens him when she was just nineteen.
They kill Magneto and Xavier along with the Avengers and X-men. She wasn't messing around this time. They start a war against machines that lasts decades. She dies in this war.
She went back to basics and decided to break the wheel for her tenth life. She went back to Charles and showed him everything. We don't know where the story exactly goes from there. But we never got to see her sixth life.