Lucas de Granville—pious, respectable, impoverished, lonely—will do nearly anything for the godfather who raised him, even though his godfather doesn’t seem to want to do anything for him.
Melisande—mundane, illegitimate, dirt poor, lonely—will do nearly anything to make sure her mother and brother have shelter and food, even though they are critical of her lack of magical talent.
When Melisande’s father, a pious comte, sends his godson Lucas to bring her to Versailles and help him train her to be a fine, staunchly religious lady, their attraction is immediate, but so is their distrust.
Her eagerness to get as much money as she can as quickly as possible gradually changes into a wish for something higher, better, and holier. Something that Lucas can help her achieve: love.