The Red Plague Affair is a slightly weaker book in my opinion, than The Iron Wyrm Affair which I managed to read last year.
The weakness lies in an oversaturation of the details and much less effort spent on character development. The world-building is beautifully done, and I do like Archibald Clare - the mentath working with the sorceress Emma Bannon.
The problem is, despite the presumed attraction and sympathy for each other, they do not really fit together as a couple, and there is no attempt to develop their relationship in some kind of romance.
Emma is an overpowering, harsh and pretty violent, self-sacrificing, bitter and cold woman, although on the inside she does get hurt a lot. There are no sparks of humour to soften her character and otherwise very dry, tense dialogues, and the reader really struggles to feel for her, because she doesn't let us do it.
Despite my misgivings about Emma, I can't fault the plot. It's a very intriguing puzzle and a race against time, while The Red Plague sweeps through Londinium and spreads through the rest of the world.
Emma has to make very radical moves, gain an enemy in Britannia - an ancient force ruling the country, and lose few dear to her people, just to stop the deadly illness. Her relationships with Mikal becomes very strange as well, as a part of his nature comes into the light while she is falling to the illness herself.
Overall, this is a very interesting read, but not one of Lily's best. That's all I can say.