Caldecott Honor author-illustrator Molly Idle offers a stunningly illustrated environmental tale featuring three very different mermaid friends who learn to coexist, in a companion to her acclaimed story Pearl. Coral, Filly, and Manta live on a sunlit reef teeming with sea life. When Coral comes upon an empty hollow at the heart of the reef and tries to keep it as her very own, Filly and Manta are banished. All that grows in the wake of her anger is regret, and Coral must find a way to turn the tide...but she can't do it alone. Caldecott Honor-winning author and artist Molly Idle has brilliantly illustrated a tale both timeless and timely, about the power of collaboration and the profound importance of caring for our environment...and one another.