Violently wrenched out of time, the TARDIS is brought crashing down onto the planet Lakertya by the villainous Rani. Caught within the maelstrom, the Doctor is forced to regenerate.Imprisoning the Doctor in her stronghold, the Rani seizes upon his vulnerable state. By impersonating his friend Mel, the Rani deceives the unwitting Doctor into helping her achieve her audacious plan. Just what is she up to? Why has she enslaved Albert Einstein and a host of geniuses? And as an asteroid composed of Strange Matter approaches Lakertya, can a weakened Doctor save the universe when he has little idea of who he really is?