The Secret Door — Janice Clark

Sammy feels as though her world has caved in when her mom has to move to another city to get work. She grasps what may be her last chance to introduce her friend Kerri to Selena's world, and the two are off on an exciting adventure to rescue BB and a group of homeless refugees. Their allies include shape-shifting elves who can turn into unicorns, and dragon-hunting, nomadic kizzees, who look a little like koalas. Both the kizzees and the unicorns are exiles from Princess Selena's home world, displaced by The Dark, and parties to an age-old feud, which complicates matters a little.