The Doomsday Quatrain, by Emma Beeby and Gordon Rennie (who I think are new writers for the Whoniverse), sees the Doctor apparently encountering Nostradamus in sixteenth century Florence; but as so often, all is not what it seems, and David Schofield is particularly good as the seer trying to make sense of a universe, and a life, which is very different to what he had thought.
House of Blue Fire, by Who stalwart Mark Morris, has a slightly different take on virtual reality; five guest stars (led effectively by Timothy West and Amy Pemberton) play the puzzled inhabitants of an abandoned hotel; the Doctor takes ages to show up and the plot then twists rather impressively at the end of episode two. Unusually, Sylvester McCoy is not on his top form, resorting to acting by Yelling Hoarsely In Terror several times, but the rest are good.
Both stories share a questioning of reality reminiscent of Philip K Dick, and also reflected in several of this year's TV episodes, though that is probably a coincidence. Good listening but probably a bit impenetrable for non-Who fans.
McCoy mentions on the extras track that he is off to New Zealand to appear in The Hobbit (which I knew) and that he was the reserve choice after Ian Holm for Bilbo in the Lord of the Rings films (which I didn't know). Looking forward to seeing him as Radagast!