Although Doctor Who visited Victorian England many a time, it was after the 2005 're-boot' that recurrent visits to the same place (London) and time commenced, with the development of a group of characters who remained constant visit to visit: the Paternoster Gang. This book empowers adventures that utilise this background and characters.
So who are the Paternoster Gang anyway? Basically they are a rather unlikely not to say unusual bunch who have come together in late-Victorian London to undertake Doctor-like roles in defending their patch from alien encroachment. They are led by Madame Vastra, a Silurian warrior no less, who was roused by the excavation of early parts of the London Underground and manages to conceal what she is under Victorian formal dress. She is assisted by her maid, Jenny Flint, who is rather more than a maid although presents as such to conform to the morals of the time... they've fallen for one another, you see, something the Victorians could not understand or condone, did they but know. So they live as lovers behind closed doors, presenting a different face to the world at large. She also has a Sontaran butler, Strax. All three are bound together by a complex back story in which the Doctor is heavily involved.
It starts off with An Age of Marvels. This covers the late-Victorian era and the Doctor's previous adventures there. Sweeping social and technological change, mostly steam-powered, mark it as a distinctive and pivotal time in Earth's history. The British Empire sprawls across the globe and fog swirls through the streets of London engulfing rich and poor alike - and the divide is wide indeed, with a clearly-defined class structure. There's a broad sweep of history, what 'Victorian' actually means and what went on throughout her reign, to enable you to capture the feel of the times in your game without getting bogged down in historical detail. There are notes on real historical figures, from the Royal Family to artists, scientists, explorers, writers and inventors. Then the narrative steps back to view everything through the lens of the Doctor and aliens being real, and being there. Timelines mix real-world and the Doctor and more to create an alternate history, and there are synopses of all relevant Doctor Who adventures (although if you want more detail you are best off consulting the appropriate Doctor Who Sourcebook from the series published by Cubicle 7 Entertainment.
Next is The Paternoster Guide to London. It's a lot more than a sourcebook to London of the time, although it is that; there's more specific material from the game point of view such as places used by the Paternoster Gang and useful contacts... not to mention some choice villains. And it opens with a delightful picture of Strax in his butler clothes pouring a cup of tea in perfect style. There's lots of detail about places to go - some real and some not - and just reading through sparks ideas for adventure even before you get to the next chapter.
Then comes Victorian Adventurers. What about Companions who come from this time and place? Or natives of it who intend to remain there and deal with any alien menaces that come their way? Here you find out how to create them, and see how the likes of the Paternoster Gang shape up in game terms... or perhaps you'd like to create your own group in similar style with whom to run your own adventures. Or they might be friends and allies of the Paternoster Gang. The options are legion, and there's plenty of material to support whatever you and your group decide to do. Yes, you too can be an alien... and there are some delightfully steam-punk Victorian gadgets to play with as well.
The Paternoster Campaign provides a wealth of advice about devising adventures and, yes, whole campaigns in this particular setting. It has a particular emphasis on the investigative style of adventure, the sort of thing Madame Vastra herself gets up to, especially when the Doctor isn't there to interfere. Again, just dipping in to this chapter starts ideas spawning and wheels turning, whether you want to bring an existing group here, create Victorian adventures as in the previous chapter and run adventures for them, or even have them step forth into the rest of the space-time continuum... the options are many.
Finally, there's a complete adventure, A Study in Flax. It's a bit of a murder-mystery, the clues leading to time-travelling mischief and people doing bad things for good reasons. There's lots going on, and several familiar characters are involved, some of them of course being alien.
This book succeeds admirably in bringing late-Victorian London as viewed from the Doctor's side alive. It will enhance any visit your group might make, or maybe inspire an entire campaign set there... but whether you merely visit occasionally or set up shop there, now you know what it's really like!