The Virtu — Sarah Monette

A disgraced wizard and a crippled thief hold the fate of Melusine in their hands...

Felix Harrowgate was a powerful wizard until his former master used Felix's magic to shatter the Virtu -- the keystone for the protections and magic of the wizards of Melusine. Now Felix's only chance to reclaim the life he once knew is to return to the city and restore the Virtu.

Mildmay the Fox was an assassin and a cat-burglar -- until a curse caught up with him. Haunted by the death of his lover, his leg damaged by the curse, he does not know what awaits him in Melusine, but his fate is tied to Felix's by blood...and by magic.

On their journey, Felix and Mildmay will encounter friends and enemies old and new, vengeful spirits, and ancient goddesses. They will uncover secrets better left buried. But nothing can prepare them for what awaits their return: Felix's former master, the cruel and decadent wizard Malker Gennadion...