When I learned of an upcoming book about a man who turns into a great white shark, I thought this was another example of our need to tame a dangerous wild animal into something suitable for a child’s tee shirt. Shark Heart, A Love Story, Emily Habeck’s first novel (Simon & Schuster, 2023) is not that at all, but much more:  a love story about newlyweds Lewis and Wren, a meditation on our relationship with the animal world, and an exploration of illness and caregiving.  Shark Heart explores the characteristics we share with other species and the question of what makes humans unique, while it also considers how health and illness affect our relationships with other people.