The story of Heart Avamir and the unicorn mother and child she befriends continues in this second part of a fantasy quartet. Knowing they are in danger if they are seen, Heart takes shelter in a cave and manages to keep the three of them alive. When Moonsilver, the young unicorn, is shot by a hunter's poisoned arrow, Heart must risk revelation to get him the help he needs from her healer friend, Ruth Oakes. Kathleen Duey again creates a story with dramatic tension and plenty of endearing touches (Heart's new puppy is almost too adorable). The book is easy enough for second-graders and uses satisfyingly rich language.