User blog comment:RoyallyBella/Mystery of the Abyss expectations blog/@comment-24864085-20140531190852

Sounds like this is a possible plot

http://believeinwinx.blogspot.co.uk/2014/04/winx-club-third-film-poster-plot.html

http://www.b-rights.com/wp-content/uploads/2014/03/Flyer-Winx-Sirenix.pdf

Hope this give us some info!