1. Some time after his twelfth regeneration, the Doctor dies for good. I can see this emotionally devastating a lot of viewers who would want to see the Doctor to go on living but from the moment we heard that the Doctor can only regenerate twelve times, we knew this day was coming. So it would be gutsy and amazing for the people in charge of the show to stand by that rule in the end.
OR
2. Just when we think the Doctor is dead for good, something happens that gives the Doctor enough energy to have twelve more regenerations. We end the series with a freshly regenerated Doctor looking forward to new adventures, new friends to make, and new enemies to contend with.
OR
2. Just when we think the Doctor is dead for good, something happens that gives the Doctor enough energy to have twelve more regenerations. We end the series with a freshly regenerated Doctor looking forward to new adventures, new friends to make, and new enemies to contend with.