watched this over the weeked - great stuff

the suggestion was that troughton-doctor was kidnapped because of a time-anomaly, which was never actually resolved as he just got into the tardis with jamie at the end and nicked off.

so is it not entirely feasible that in the overall doctor who universe that a second doctor still exists ??

obviously he would have re-generated a few times at least by now, but they made no attempt to reset the balance and return troughton-doctor to his timeline, so i would say it's still possible.

future storyline maybe ?

Another explanation for how the 2nd Doctor was able to be in this adventure was an untelevised series following on directly from the end of 'The War Games' - Season 6b, you can read up on it here:- http://en.wikipedia.org/wiki/Season_6B