There are 43 books in the Alfred Hitchcock and the Three Investigators series.
The Alfred Hitchcock and the Three Investigators series does not have a new book coming out soon. The latest book, The Mystery of the Cranky Collector (Book 43), was published in January 1987.
The first book in the Alfred Hitchcock and the Three Investigators series, The Secret of Terror Castle, was published in January 1964.
The Alfred Hitchcock and the Three Investigators series primarily falls into the Mystery genre. This middle grade series was written for ages 8-12, but can be enjoyed by older readers as well.