To save the Goblin King, she must risk her life on a journey to the ends of the faerie realm.
Freya couldn't have known she would destroy the entire faerie court by beating the Goblin King. All she wanted was her sister back, not to imprison the king. But with her sister refusing to return home, Freya is left trapped in her own mess. She has to fix what she broke or the faerie realm will get infinitely more dangerous.  
Bring the Goblin King back. Save the people she harmed. And do her best to avoid the temptation of falling into the Goblin King's arms. Considering the Goblin King is locked away in a magical prison, at least one of her goals may be impossible to achieve...unless she's willing to go through hardships unnumbered.