Aaron+Henna:The Way of The Rat

Volume five of the Aaron+Henna series:
Dealings in the big city are nothing compared to infighting in small towns.

A failed apprentice blasted by dragon magic and a (pregnant) tea-witch try to finish building a wizard's tower to live in;
Inquisitors from the church, jealous rivals and meddling nobles all contribute to the fracas and fight over dragon magics.
Harvey and the old witch deal with troll smugglers as Aaron tries to sell dragon-hoard treasures.

And a new apprentice (healing) witch spells trouble for all.