Lithium (Once Upon a Time)

Emma and Regina finally get married and their book closes as all the people in Storybrooke embrace themselves to live their happily ever after. They spend their romantic honeymoon travelling throughout the realms, searching for adventure. But when they thought they'd return to Storybrooke, they encounter a realm they never thought to be real, with stories much darker than the fairytales they were used to.
Now trapped in the Land of Untold Stories, Regina faces secrets she thought to be buried by the sands of time, including the person she hurt the most: the prince of vengeance, Hamlet. Can she trust Emma with her darkest sin, if it means showing her the depths of darkness in her soul? And if she can be honest with her beloved swan, what will stop Hamlet from destroying Regina's new found happiness?!
For the prince of darkness its simple, the queen must pay for what she did to him. So, he changes the past and paints Storybrooke's fairytale with the crimson look of tragedy. And as a new destiny is formed, the secrets the Charmings and the queen had buried come to the surface to challenge Regina and Emma's love and inevitably kiss the swan into fading in everlasting darkness.
The dark swan shall rise, for this isn't a fairytale anymore, dearies, Muah, ah, ah, ah, ah!
(NOTICE: This book follows Once Upon a Time: Finding your story, my stepbeliever fanfic with over 6k reads! ;)