A pair of young whale sharks swim through warm ocean waters, when all at once, they're trapped—caught in a giant fishing net. What will happen to them? Why is it critical that they escape? Whale sharks are the biggest of all sharks. But despite their size, scientists know little about them. Scientists do know that despite the marine sanctuaries set aside to protect these gentle giants, fewer whale sharks have been sighted in recent years, and most of those are young males. Where are the young females? Where are the adults? And why are the sharks appearing in parts of the ocean where they haven't been seen before? Scientists are racing to find out more about these amazing endangered animals, which face threats from both commercial fishing and from climate change. They may be accidentally caught in fishing nets, fished by poachers, or hit by a ship's propeller. But innovative new conservation methods, which include enlisting volunteers to spot them as well as tagging and remotely following them—are giving experts hope. Can volunteers and scientists help save the world's biggest fish before it's too late?