When Colgate, Ponyville's premier and only dentist, has a crisis of identity, she is swept up on a mad run through space, time, and beyond. Meanwhile, Sunset and a Trixie have borrowed the TARDIS.
Fleeing from the Time Lords the Doctor accidentally damages the barrier between his own universe and that of Equestria an event that may lead to disaster for both universe. Now he must visit Equestria again and again to solve the problem.
Sent on a mission by his fellow Time Lords, The Doctor attempts to stop the Daleks from ever being created. But it's actually easier said than done. A ponification of Tom Baker's most famous story.