Ever since Penelope Tench was in grade school, she knew there was no one living on Colony Island she was interested in choosing as a mate. There were feral boys-merfolk who lived in the ocean-but they were not a viable choice. Penelope could only spend three days at sea before wanting to return home to her warm bed and a hot meal. She wanted to find a mate and have a family someday, like most females, with or without scales, but as she grew up, her chances lessened, as there seemed to be only one option left-and mermaids were strongly advised not fall to in love with humans.

After...