A horrifying scene: a family of four is out to sea on their yacht, there are explosions and fire, the teenage girl panics and jumps into the water even though sharks are there. They attack her, and her brother jumps in to help, but, neither are seen again and there is only blood around. The parents eventually are rescued.
It turns out the boat ran aground on a sandbar. Somebody moved a buoy, causing the accident. Wolfe and Calleigh can't do a lot of investigating int he boat, because it's sinking, but they do learn a few things, such as where the fire started and that it was not an accident.
To say there are a ton of twists in this story is understating the case. It's unbelievable. Nothing, absolutely nothing is how it looks from that beginning. A very interesting show which gets better and better as the surprises mount.