Lucy and Fred are working on a Field Guide during their summer vacation. They write up any animals they encounter. When a white shark is caught in a fisherman's nets they decide to include it. The shark leads them to Lucy's mom who was a marine biologist and died several years ago. She was an expert on sharks and had many papers for them to refer to. Then tragedy strikes Lucy's young life for a second time. She is left on her own and turns to the sharks in her grief. She follows the trail laid down in her mom's last research paper. She is aided by her dad, her elderly neighbor and her fisherman friend.

I enjoyed Lucy's story but it was terribly sad and tragic, probably overly so for a middle grade book. It was also really long with a lot of detail that could have been consolidated. Young readers like a bit more concise story and this one meandered. I don't think the second tragedy of Lucy's life was really necessary. I think she could have gone on her journey to discover her mom's work without that motivation. There seems to be a trend of tragedy in realistic fiction for middle grade right now and I think it could end any time soon.