Harry Hammer looks for the lost treasure of Long Fin Silver, the greatest pirate of the deep seas, in this ninth Shark School (mis)adventure. Harry Hammer can't believe his luck! He and his family are going on vacation to Treasure Reef, home of The Lost Treasure of that dastardly, long-ago pirate Long Fin Silver. Legend has it that Long Fin buried the Black Blood Pearl, the most valuable and beautiful gem in the history of the ocean. Harry and his pesky cousin Harvey are on the hunt for treasure, but they best beware of where they look, as they're about to come fin-to-fin with the spooky spirit of Long Fin Silver himself!