The fourth book in The Chronicles of Narnia series by CS Lewis is The Magician's Nephew which, has been currently revealed to be the next Narnia film.
Walden Media co-founder and president Michael Flaherty told The Christian Post that the company started talking to Fox and CS Lewis estate about making The Magician's Nephew to be the next film in the series. Liam Neeson and Tilad Swinton could be returning to reprise their roles as Aslan and the White Witch.
The fourth book tells about the creation of the magical world of Narnia by Aslan and how evil first entered it.
Flaherty stated that if all agreed "to move forward" with the project that they next step would be finding someone to pen the script. This could take up to two years.
The first three films in the series are The Lion, The Witch And The Wardrobe, Prince Caspian: The Return To Narnia and The Voyage Of The Dawn Treade. CS Lewis wrote seven books in his Narnia series.
SOURCES: Press Association via Yahoo!UK; Image