For the first time, see Katie's 17th through 20th mysteries together in one volume, along with a special never-before-published short story! First, in the Case of the Roman Treasure, an old family friend asks for help in tracking down her father's secret treasure. Then, in the Florida Shark Mystery, a small town on the coast has a shark problem, and Katie's cousin and uncle need help solving it. Next, in the Case of the Double S Pendant, a famous singer is being stalked, and a famous gentleman thief may have something to do with the case. Finally, in the Mystery of the Banshee's Curse, Carl has been fingered as a cursed member of the family while on a vacation to Ireland, but Katie is determined to prove that the banshee isn't real. And lastly, in Jean and the Mystery of the Haunted Painting, Katie's mother investigates a mystery of her own when she volunteers to paint over a canvas that turns out to be haunted!