简介：The esteemed physician is compelled to revisit Gallifrey, yet the weight of the bureaucratic chores and the impending official scrutiny stemming from Romana's actions in the preceding escapade looms heavily upon him. Nonetheless, he persuades Adric to detour to Earth, suggesting they gather some data from a police box en route to Logopolis, where the Chameleon Circuit requires urgent repairs. Upon their arrival on Earth, the Doctor's keen senses detect an anomaly. A temporal anomaly has manifested, resulting in a TARDIS materializing within another TARDIS—a phenomenon he fears could lead to an infinite regression. Should this be the case, both he and Adric could be ensnared in an eternal limbo. Simultaneously, Tegan, a down-under airline stewardess, inadvertently stumbles into the Doctor's TARDIS after her vehicle succumbs to mechanical failure.