Fear for your life, the monsters have returned. All nine books in one package - the complete set of Monster Case Files. The monster. What is it? Where did it come from? Grace and Henry Warner need a killer senior project if they want to get into Stanford and MIT. Urban myths. Legends. Wives tales. While traveling around the country with their parents, they had the perfect opportunity to learn more. They peeked behind the curtain, where they find that not everyone tells the truth. The twins are trapped into figuring out what's real and what's not. And they won't be safe until they do. Join Grace and Henry on their journey through a life of travel and mystery with parents who believe in them, as long as they aren't completely sure what the twins are up to.