When the ominous theme song to "Jaws" rings on his cell phone, fish-obsessed sixth-grader Barn Whimbril knows a shark attack has been reported. Barn tracks attacks from all over the world. But this time, it's right in his own backyard - a series of canals near coastal Florida. As more sightings of these aggressive bull sharks occur in the area, Barn sets out to investigate. Can Barn figure out what has brought these sharks to a once-quiet part of his state before another attack occurs?