Two Necromancers, a Bureaucrat, and an Elf

I always include major spoilers (hidden), to help with my memory  issues. Read them at your peril! 

A necromancer and Katy, his 10 year old feisty apprentice, are offered a pardon by a government bureaucrat if they carry out a few dangerous jobs for their country, which is under threat. They set out with the bureaucrat, and Katy's ninja rats.  They meet a devious elf who can produce huge amounts of heat and fire, defeat her, and she joins them on probation.  They defeat the titular army of golems and then move on to an even greater challenge, meeting the so-called “old man” on the way 

Entertaining, and a different kind of fantasy novel. Less slick, with darker, more snarky humour, and absolutely no heroes.