Ben, a young Irish boy, and his little sister Saoirse, a girl who can turn into a seal, go on an adventure to free the faeries and save the spirit world.

Bronagh: My son, remember me in your stories and in your songs. Know that I will always love you, always.
Conor: [on his daughter's seal skin] I threw it away... I should've done it years ago
Conor: [locks his daughter's seal skin in a chest which he throws overboard] I lost you Bron... I can't lose her as well
[repeated line]
Ben: Holey Moley
[repeated line]
Ben: Holy Mary and Joseph
Ben: [to his sister] are you really a selkie?
[first lines]
Saoirse: Ben
[last lines]
Saoirse: Granny