Book #2 in The Dauntless Quaternity Series, EYES OF THE ICE OWL.

A mysterious rider on horseback arrives in Qibar, talking of a monster in the North Mountains. He claims a legendary presence has returned -- the fabled Ice Owl -- and the only chance Arrowpoint Island has from not becoming a permanently frozen wasteland, is the heroic Dauntless Quaternity. But when their journey takes them deep into the mountains, they soon realize that all is not what it seems to be, and it may be too late to save the land from doom..