Katie has always loved her quiet life in Adventure Bay, caring for the animals, helping Ryder, and keeping the pups healthy and happy. But when a strange visitor leaves behind an old locket with a royal crest-and a warning-everything begins to unravel. Ryder finds an old photo tucked into the back of Katie's desk drawer. It's a blurry picture of a little girl in a golden dress... standing beside a queen. As he and the pups start investigating, mysterious clues begin to surface: a forgotten lullaby Katie hums in her sleep, an old scar that matches a description in a missing persons report, and a sealed letter written in a language only royalty would know. As the truth unfolds, Katie discovers a heartbreaking secret kept hidden for years: she is the lost princess of the Kingdom of Aldoria, taken as a baby and hidden in Adventure Bay for her safety after a betrayal in the royal court. But now, her enemies have returned-and they know where she is. Torn between the life she's built and the crown she was born to wear, Katie must decide who she really is-and whether she'll return to reclaim a kingdom, or stay with the only family she's ever known. But danger is closing in fast, and the pups might have to risk everything to protect their beloved Katie... even if it means saying goodbye.

It is summer vacation for beacon academy, and for Team RWBY and Team JNPR.....they are bored. That is until a mysterious message appeared on Ruby scroll, offering her and her friends to play a game they have never heard of. Well, there's only one thing to say: IT'S TIME TO D-D-D-D-DUEL!!!