The Ghost of the Chattering Bones   The Alden children knew there was a mystery at Eton Place, but they had no idea there would be a ghost there, too! A family friend believes there is a valuable piece of jewelry hidden on her property, but she only has one clue to help them find it. Will they find the treasure, or will the ghost of the Chattering Bones scare them away first?   The Creature in Ogopogo Lake   The Aldens are visiting Grandfather's friend Abby in Peachland, Canada—home of the mysterious lake monster called Ogopogo. When the children learn that Abby must sell her resort unless she can attract more business, they decide to help. But someone or something is trying to get in their way. Can they save the resort?   The Vampire Mystery   Henry, Jessie, Violet, and Benny meet Mr. Hudson, a local author who is best known for his novel about a vampire. But rumors of a real vampire are going around town—a vampire who haunts the graveyard behind Mr. Hudson's house! Since vampires don't exist, the children soon realize that someone must be trying to scare people away! Who brought the old legend back to life—and why?