Charlie Bone and the Blue Boa is the third novel in the Charlie Bone Series. It is also known as Charlie Bone and the Invisible Boy in the U.S. version. Its prequel is Charlie Bone and the Time Twister and the sequel of it is Charlie Bone and the Castle of Mirrors.A boy was once lost in the attics and never seen again. Charlie Bone is intrigued, but he has problems of his own