Doom is currently traversing all of time and space in pursuit of the Doctor, who is the only one who can save her from the ever-approaching Death. Instead, she's found Missy, a morally ambiguous Time Lord posing as the Doctor, who has taken it upon herself to stop Doom's killing spree. (Or is she just after the Perpetual Topaz Doom stole before she had the chance to?) With Missy hot on her trail, Doom has less than 24 hours to save herself before her fate is sealed forever...