Martha was a mutant runaway who was captured by the human supremacist group, the U-Men. Their founder John Sublime had her brain removed from her body, keeping the disembodied brain alive in a capsule. She has the power to negate any mutant's powers, like Leech. Sublime controlled her through drugs and syringes and used her to subdue his opponents, the two X-Men, Cyclops and Emma Frost. The two X-Men eventually broke free of her control, after which Martha took her revenge on Sublime by causing him to fall to his death.
She later became a student in the Xavier Institute's Special Class. Quentin Quire invented a special hovering case to hold her brain, usually linked to a chain held by Ernst, a mysterious, super-strong mutant appearing like an old woman, who often repeated Martha's telepathic communications.
It is revealed that Martha was one of the students that had joined Xorn's new Brotherhood of Mutants, alongside Ernst. However, Martha's loyalty would not last as she predicted that Xorn's scheme to murder every human in Manhattan as well as turn the planet earth upside down would fail miserably. Following Xorn's death, Martha has not been seen again.