Dream a Little Dream — Piers Anthony

Nola and Tina are both girls with problems. They don't know each other yet, though they will; each is a Creator, with the magical ability to turn dreams into reality. That would be a powerful gift--if either knew that she had it. And this world is hard on dreamers. Nola is trapped in a terrible, abusive relationship with a man she once loved, and Tina is an orphan who makes her living on the street. All their dreams are slowly being ground into dust.

That's a tragedy no matter who it happens to. But when the great dreamers stop dreaming, whole universes of imagination can be lost. And the land of Nola and Tina's dreams is fighting back.

Into their miserable everyday world soars Espirit, a winged unicorn dark as the space between the stars. he is the vessel of Nola's dreams, come to aid her in her battle, with sordid reality. Following after him comes Prince Michael, whose quest it is to find the human dreamers who can save his land from ruin.

And suddenly, Nola realizes that the last thing she wants is to keep both feet firmly on the ground...