Book 4 of the Invisible Library series. Spoilers ahead
Irene tries to get a book in a fair book exchange, and finds herself in a lair of vampires. Extricating herself, she meets up with a dragon who tries to make a deal. And notes this was carefully timed to ensure that Kai would not be with her.
When Kai returns early, he can tell her some things, but exposes her to danger because now the other dragon knows.
Consequences touch on Irene's mysterious past, taking the train from Boston to New York, appropriate attire, a newspaper account of a master hypnotist, Irene's losing her voice, a lot of bath-tub gin, a fae not involved in their problems intentionally, a copy of The Journey to the West, an unexpected daughter, a dead mentor, and more.