The peaceful waters of Trident City are suddenly filled with panic. A group of aggressive, sharp toothed sharks has invaded the area, and they are causing serious trouble for all the merfolk. The citizens are terrified to leave their homes, and the students at Trident Academy are put on high alert. Shelly, Echo, Kiki, and Pearl know they need to stay safe, but they also want to understand why these dangerous predators have suddenly swarmed their usually quiet neighborhood. The four friends must bravely investigate the changing ocean currents and figure out what is driving the sharks so close to the city. This action packed chapter book takes young readers on a thrilling, high stakes adventure beneath the waves. It delivers a perfect blend of suspenseful mystery and fascinating marine biology, showing how courage and teamwork can help calm even the most dangerous waters.