So Silver Bright (Théâtre Illuminata #3) by Lisa Mantchev

Act Three, Scene One
Bertie thinks her quest is almost done. With the help of Ariel and the rest of her friends, she has managed to find her father and rescue Nate from Sedna, the Sea Goddess. Now, all she has to do is reunite her father, the Scrimshander, with her mother, Ophelia, and she will finally have a true family of her own.

Exit Stage Right
However, things are never easy for Beatrice Shakespeare Smith. Her father has vanished, Sedna is out for revenge, her own actions have trapped the Théâtre Illuminata in a strange kind of limbo, and the stress of her in-between state is tearing apart the fragile threads of her mother’s sanity. Bertie’s best hope for salvaging the situation may lie in a summons by Her Gracious Majesty, Queen of the Distant Castle, and the hope of winning the magical boon given to the best performance.

Bertie is caught between her growing responsibilities to home and family, and the dream of flying free – just as her heart is torn between her two loves, Nate and Ariel. With so any forces pulling on her, how will Bertie be able to choose which wish to make come true?