Winona Williams wanted to start a new life back in her hometown of Arcadia Oaks, California. After finding a letter addressed to her from her cousin, she'll get more than what she bargained for.

When Jim's older sister, Monica Lake, comes back from college, she is surprised to hear from her mother that Jim hasn't been himself lately. That he's been getting into trouble. When she discovers why, she receives the adventure of a lifetime.

After the events of season 3, instead of leaving for New Jersey, Merlin is able to fix the heartstone and the trolls stay in Arcadia. Dictatious and Blinky are learning to live together once more, but old wounds still sting, and Blinky finds himself struggling to forgive his brother's past mistakes. Can the two trolls find a new way to accept each other and make a fresh start? *original idea suggested by @elliesjones , thanks!*