What is the secret in Secret of the Wings?

Tinker Bell and the Pirate Fairy (2014)



The series in order is:
Tinker Bell (2008)
Tinker Bell and the Lost Treasure (2009)
Tinker Bell and the Great Fairy Rescue (2010)
Pixie Hollow Games (2011)
Secret of the Wings (2012)
Tinker Bell and the Pirate Fairy (2014)