The book drops Doc and Yoyo with six swans. Those are actually princely brothers, who regain their human form only at night. They can break the spell and regain their ancestral kingdom from usurping witch Maledivia, but only if their sister makes for each of them a sweater spangled with rare star-shaped flowers, which they must collect by day from a dangerous swamp. The witch-queen's son, Prince Wolf, wants to help them because he loves the sister, but his evil mother prefers the swan throne to him and sends her soldiers to wreck them all and the flowers.
—KGF Vissers