The Haunted Museum series does not have a new book coming out soon. The latest book, The Cursed Scarab (Book 4), was published in May 2015.
The first book in The Haunted Museum series, The Titanic Locket, was published in May 2014.
The Haunted Museum series primarily falls into the Horror genre. This middle grade series was written for ages 8-12, but can be enjoyed by older readers as well.