on November 29th, 2013 at 02:03 am
General consensus is: that wasn't Four. That was Doctor N, where N had decided to regenerate into a familiar face for his retirement (other Time Lords have had control over regenerations in past. I think the Doctor's are generally just too traumatic.) I can't recall the exact quote, but the curator actually uses words to that effect. Gets around the aging thing quite nicely.
Other than that, I'm fully on board with Osgood being companion. :-D