All Doctor Who books should be like this. This is pretty much the perfect Fifth Doctor novel. Two of my favourite Big Finish audios are The Reaping, bringing Peter Davison and Janet Fielding together again, and The Bride of Peladon, where the Doctor ends up dealing with the Osirans from Pyramids of Mars. Sands of Time has Five and Tegan battling against the servants of the Osirans, helped mainly by Atkins the butler who comes along in place of Nyssa, who is abducted at an early stage of the book. Many glorious references to PoM, of course, including one squeetastic moment at the end, but also mentions of Black Orchid and City of Death. (And Arc of Infinity, but nobody's perfect.) There's also a certain amount of sober reflection on the Doctor's ability to stay both inside and outside the flow of Time, with his final victory coming as the result of a very neat bit of sideways thinking. (Several times over, which is a bit surprising.)

You don't even have to pay for the delightful experience of reading this book, cos you can download it for free entirely legally from the BBC website, plus illustrations which weren't in the original publication. Any Who fan who doesn't actively hate the Fifth Doctor era will love this. (Not so sure how accessible it would be to the non-fan, but would be interested to hear from anyone who dares try the experiment.)