The quick-witted (and rarely quiet) mer-prince Castian is ready for an adventure. A sketchy deal with a sea witch gives Cas legs and the chance to join brooding Captain Valentine’s rag-tag pirate crew aboard the Scarlet Mamba. Plenty of high jinks and sassy banter take these lovable characters through secret missions and run-ins with monsters—and they occasionally stir up some unexpected emotions. Oh, and did we mention there’s a musical number?