Events in The House of Binding Thorns follow on pretty much immediately from the ending of the previous book (The House of Shattered Wings), which I re-read just before starting this book since it had been a while since I first read it - the previous book stood up to re-reading but this one wasn't quite as impressive.
Anyway, hot off the difficulties experienced by House Silverspires in the previous book, including being taken over by an enormous banyan tree as part of an act of revenge by someone who the House's founder had betrayed and allowed to be killed, The House of Binding Thorns follows what happens to a couple of the characters we met previously as well as introducing some new ones.
Philippe, former dragon and exile in Paris, is one of them though he's mostly kicking around as a supporting character in this storyline, with more attention being paid to the fate of Madeleine. She's still finding her feet in her new/old House when she's sent on a mission to the dragon kingdom under the Seine, as Asmodeus is looking to make a marriage alliance.
The dragons are in trouble, though - their kingdom is ravaged by the same addiction that Madeleine had and the dragons suspect House Hawthorn is behind it. Meanwhile another House is taking advantage of the relative power vacuum left by the problems of Silverspires and trying to both oust Asmodeus and help rebels take over the dragon kingdom.
All in all, still an enjoyable read and enough going on towards the end of the story to keep me interested in finding out what happens next, though it does drag a little bit towards the middle. There's a whole sub-plot with Asmodeus' fellow Fallen which doesn't really go anywhere, except to get her into Hawthorn and doubtless set up future storylines and that's a little frustrating.
One other problem: the paperback edition I read had incredibly small print, like about 2 points smaller than usual. I do a lot of reading in bed and that was really hard to read for extended periods of time!