In the depths of the big wide sea, the little jellyfish hears a loud THOOMP. What is this mysterious sound?With magical collage illustrations, this is a joyous, read-aloud picture book about the uniqueness of every creature's heart. A wise fish explains to the jellyfish that the loud THOOMP is a heartbeat. The jellyfish listens to the soft heartbeat of the wise fish. Sadly, she realises she has no heartbeat herself though, and she still needs to find the very loud THOOMP. So off she swims to search for it. Along the way, she meets all kinds of creatures and learns about their heartbeats, from the seal to the whale to the octopus that has three hearts! But why can't she hear her own?Packed with fascinating scientific knowledge, including extra pages about the unique hearts of more amazing creatures, this engaging book conveys the incredible diversity of life on Earth, and encourages everyone to love how they are different and to celebrate being themselves.