Born out of the necessity of changing actors came one of the iconic concepts of Doctor Who, the regeneration. This provided a convenient explanation for why it was still the Doctor even though he looked and acted quite differently. The grumpy old man played by William Hartnell became a more playful figure in the hands of Patrick Troughton.
The first chapter introduces regeneration, the second Doctor and his companions. There's an extensive analysis of the character and nature of this regeneration, showing how he brought a completely different outlook and approach to every situation... as well as a full character sheet should he happen to turn up in your game. Likewise, all the companions that travelled with him - beginning with Ben and Polly who'd been with the original Doctor as well - are presented with copious notes and character sheets. The chapter ends with a few notes on the TARDIS, which remains pretty much the same as it was.
The next chapter is Tools of the Trade, but starts off talking about companions and the various options open to you, not just whether to use ones from the show or come up with your own, but about theire different reasons for joining the Doctor, agreeing to stay and, eventually, deciding to leave the TARDIS. There are also comments about using these adventures with different Time Lords (perhaps not even the Doctor at all) or without one, although the wide-ranging nature of the adventures described in this book means that access to some kind of time-travel device is virtually essential. Some new Traits and Gadgets are also provided here, many will have more general application than the reason that they are included.
Chapter 3: Enemies provides details of some major recurring enemies starting with the Cybermen - of which there are several different versions, not to mention Cybermats, Cyber Controllers and Partial Cybermen (who are, of course, mentioned!). There is a similarly in-depth look at Daleks, as well as the Great Intelligence, Yetis and Ice Warriors.
Then, Chapter 4 looks at designing adventures, with an eye to creating ones with the right look and feel for the Second Doctor era. Even if you intend to use the adventures from the show, it's worth reading - particularly as many episodes have been lost so you cannot study up by watching them! This, of course, makes it a bit easier to re-use adventures as unless your players are as old as I am they probably haven't seen them either. There's a lot of material here, of general use even if you don't want to use much Second Doctor material.
We then launch into the actual Second Doctor adventures, some twenty-one of them. For each, there's a synopsis of the adventure itself, notes on how to run it in your game 'as is', material on notable creatures (including NPCs) and artefacts encountered (which you may wish to use elsewhere, of course) and ideas for further adventures based on it. This gives an impressive array of options for how to use some or all of the material in creating your game.
Whether it inspiration or complete adventures - or just an exploration of one of the lesser-known Doctors - that you are after, you should find plenty to amuse you here.