There are 2 books in the Unbelievable Oliver series.
The Unbelievable Oliver series does not have a new book coming out soon. The latest book, The Unbelievable Oliver and the Sawed-in-Half Dads (Book 2), was published in May 2020.
The first book in the Unbelievable Oliver series, The Unbelievable Oliver and The Four Jokers, was published in May 2019.
The Unbelievable Oliver series primarily falls into the Mystery genre. This chapter book series was written for ages 7-10, but some older readers may still like to read these books.