'The Taking of Planet 5' by Simon Bucher-Jones & Mark Clapham
(Just to remind you, the readlong featured book is one that has been widely approved of, and is the book you should read if you only have the time or inclination to read one EDA this month).
'The Taking of Planet 5' follows directly on from 'Blue Angel'... bits of 'Blue Angel' anyway. I'm not going to lie to you - even though this is a lot more straightforward than that, I still find it very confusing (don't worry - the straightforwardly good 'Frontier Worlds' is up next! I love that one). 'Taking of Planet 5' is a sequel to 'Image of the Fehndahl' - sort of. It still features Fitz and Compassion, we're still big into the Time War plot (it's important later) and so some old 'friends' from earlier in the series show up. There's some Lovecraft, and some paradox stuff. Both authors have done various other stuff in the Whoniverse, but I think this is the big thing of note.
Please put spoilery comments behind lj-spoiler cuts or white-out the text below an indication of where you are in the book. And please comment and discuss if possible!