I just saw "The Deadly Assassin", the Tom Baker serial which resurrected the Master, introduced us to Gallifrey, and introduced the twelve regenerations concept. We're told a Time Lord can only regenerate twelves times before dying, and this is what happened to the Master. But the Master had a plan; by accessing the Eye of Harmony he could absorb its energies to revitalize himself and gain new regenerations.
So this could be how the show continues after its twelfth actor leaves. The Doctor just needs to expose himself to the Eye of Harmony and he'll get new regenerations.
Gallifrey was destroyed, but what if the Doctor took the Eye and put it in his Tardis for safe keeping before he blew it all up?
The only problem with this is that we've seen the Tardis requiring the Cardiff Riff to recharge in "Boom Town" and "Utopia". But maybe the Doc just doesn't want to expose the Eye unless he has to since its all that's left of his people.
So this could be how the show continues after its twelfth actor leaves. The Doctor just needs to expose himself to the Eye of Harmony and he'll get new regenerations.
Gallifrey was destroyed, but what if the Doctor took the Eye and put it in his Tardis for safe keeping before he blew it all up?
The only problem with this is that we've seen the Tardis requiring the Cardiff Riff to recharge in "Boom Town" and "Utopia". But maybe the Doc just doesn't want to expose the Eye unless he has to since its all that's left of his people.