There will be eithere four or five. The fourth one is still pretty new.
There are 15 books in the series.
15 and 7 short stories
There are 15 books in the Secret Seven series by Enid Blyton, each featuring the adventures of a group of child detectives who solve mysteries together.
The Secret Zoo is by Brian Chick. The book has 320 pages. It is the first book in a series of five books.
There are a lot of books by Enid Blyton, such as The Famous Five series, The Secret Seven series, The Five Find-Outers series, and many more. Like the Noddy series, some of which are reviewed here noddybooks.blogspot.com
Enid Blyton
The secret is: the other side... read the fifth book if you want to learn more about it
The author Lisa Smith has written several series of books. Her books include The Night World Series, The Vampire Diaries and Series, The Secret Circle Series, and The Forbidden Game Series.
To find books in the Secret series, consult a bookseller or librarian.
The order of The Secret Circle series of books is:The InitiationThe CaptiveThe PowerThe DivideThe HuntThe Temptation
The five books in Pseudonymous Bosch's The Secret Series are, in order:The Name of This Book is SecretIf You're Reading This, It's Too LateThis Book is Not Good For YouThis Isn't What It Looks LikeYou Have to Stop This
There are 4 books in the series.