Fairest in the Land — Barbara Hambly

A novelette of 11,500 words. As Princess Tinomiel's wedding to a charming prince approaches, she falls prey to what her parents are pretty sure is a curse: she falls asleep constantly, and sleeps for longer and longer. They hire former mercenary captain - now turned wizard - Sun Wolf, and his warrior partner Starhawk, to find the malignant Night Queen who is believed to have placed the curse on this perfect Princess. But Sun Wolf and Starhawk find that they may be in as much danger from the three Good Fairies who supposedly blessed the Princess at her birth.