Fly Trap by Hardinge, Frances-Paperback

Mosca Mye and Eponymous Clent are at it again. Escaping disaster by the skin of their teeth, they find refuge in Toll, a strange gateway town where visitors may neither enter nor leave without paying a price. By day, the city is well-mannered and orderly; by night, it’s host to rogues and villains. Wherever there’s a plot, there’s sure to be treachery, and wherever there’s treachery, there’s sure to be trouble—and where there’s trouble, well, Clent, Mosca, and Saracen can’t be far behind. But as past deeds catch up with them and old enemies appear, this time, it seems as if there’s no way out.