The 1st of the 2nd generation Doctors (Peter Capaldi) and his Companion Clara have a new Mission
After all 12 of the Doctors incarnations secretly froze Gallifrey in a pocket Universe in 'The Day of the Doctor' a future incarnation (Tom Baker) charged The Doctor with finding his home planet
Following clues and threads layer out across his previous generation Cycle they embark on a series long quest. A quest that takes them to the furthest reaches of the known universe and Across the Event Horizon.
But What horrors await him in this Multidimensional quest.