Somewhere in Saint Erasmus's Catholic church, there's a parish register containing a firsthand account of the sinking of the "San Telmo." To find that ship in honor of their murdered aunt, Chris and Carrie first have to find the register. And it turns out that the church is supposed to be very haunted.

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.

"Marly, Sai, and Isla are back on the hunt. After finding Mr. Summerling's hidden treehouse, they've discovered a new set of clues for them to follow, leading them straight to the heart of their mysterious neighbor's life: his house. The same house Marly has been living next to all of these years, which, they discover, is filled with hidden rooms and staircases. With just a few scraps of papers as clues, and Mr. Summerling's angry son on their tails,...

Mr. Summerling, Marly's neighbor, talked about being a treasure hunter, and news of his death has brought Marly into a treasure hunt of her own. In his will, Mr. Summerling left a treasure for Marly and two classmates, Isla and Sai. They barely know each other, but they have to work together with a series of riddles, puzzles, and clues to find the treasure.

When the city of Zollicoffer, Tennessee, where her family lives, announces plans to seize their one hundred seventy-five year old house through eminent domain, twelve-year-old Louise Mayhew needs to come up with a way to save it--and her ancestor's Civil War diary linking the house to the Underground Railroad, as well as a hidden treasure, seem to offer her family the best chance of saving their home.