In this mystery set on a tropical island, three middle school-aged kids accompany a marine biologist to help with ocean life research. The action picks up when suspicious strangers behave threateningly toward the main characters, and when they rescue an older woman from a possible shark attack, their questions increase. As a part-time resident of one of the Family Islands, I was pleased with the focus on Bahamian island life, and found the descriptions of the people and lifestyle to be authentic. Although the plot may seem rather implausible, the pace is quick and the conservation principles are well-grounded. ( )