"Frank and Joe are off to the Florida Keys to work alongside Lookout Shark Lab's Dr. E. Ella Edwards, one of the world's foremost marine biologists. On their first evening, Dr. Edwards paddleboards out to check on a lemon shark nursery. But after a sudden squall rolls in, she doesn't return, and the next day her board washes up with a shark bite taken out of it. The Hardys volunteer to help the search and rescue efforts as panic sparks a rift in Lookout Key. Half the town is determined to get rid of the shark threat; the other half wants to protect the shark population and Dr. Edwards's vision. But as Frank and Joe learn more, the whole situation seems increasingly fishy. Lookout Key is full of secrets, scheming, and a lot of people whose lives would be easier if Dr. Edwards and her conservation efforts disappeared for good. Can the brothers discover the truth before it's too late?"--Page  of cover.
Dixon, Franklin W. Hardy Boys adventures ; bk. 21.
Hardy boys adventures
Hardy boys adventures ; #21
Florida Keys (Fla.) -- Juvenile fiction.
Hardy Boys (Fictitious characters) -- Juvenile fiction.
Marine biologists -- Juvenile fiction.
Missing persons -- Juvenile fiction.
Detective and mystery fiction.