Takes up where Nice Dragons Finish Last leaves off, almost. Spoilers for that ahead. So, back to the alternate history where magic returned and Detroit is the private preserve of a lake spirit. . . .
It opens with the reappearance of Estella from the last book and her using magic on her sister Svena.
Meanwhile, Marci and Julius have started their business, though Julius's scruples about bounties on harmless creatures has limited their money making. But then they return from a job, and find his mother there. Haughty and arrogant -- Julius barely manages to keep Marci alive because she babbles -- Bethesba has come to drag Julius off to a party. She had invited Svena and Katya using his name, so she needed him.
On the other hand, when Estella shows up, she's a surprise there, too.
The plot involves why the dragons are here at all; what Marci's spirit-cat Ghost really is; an offer from another dragon to Marci, to drop Julius and join her instead as her human; the powers of a water spirit over things dropped in its waters, and their limits; Julius's booking Katya an airplane ride; a body left in an alleyway, forgotten; and more.