"To Maintain the Balance" by Jamie Lackey appeared in Daily Science Fiction on March 7, 2013. "A princess seeks the aid of a unicorn to lift a terrible curse."
Like the author, I have a soft spot for unicorns, perhaps the most beautiful of mythical creatures. I also appreciate the nod to ancient Greco-Roman mythology in this story, which, while entirely original, reminds me of so many of the stories in Ovid's Metamorphoses that feature a beautiful maiden princess who spurns all suitors, particularly the story of Atlanta.
Ms. Lackey creates the perfect mood of desperation and hope. The device she uses to end her tale is unique and deliciously horrifying, evoking a feeling of poetic justice and intensifying the mythological feel. 6 out of 7 rocket-dragons.