Ms. Rose is the Plant Person Empire from the PC game, Cluefinders 6th Grade Adventures: The Empire of the Plant People.
Plot
When pollution from the factories in the Cluefinders' hometown starts to interfere with Ms. Rose's kingdom down below, she disguises herself as a human lady to go up to the surface to see what she could do. She then plans an evil scheme for her Plant People Army to go up to the surface and attack the Cluefinders' hometown.
When the Cluefinders meet Ms. Rose in her true form as the Planet Person Empire, they decide to help her by fixing the pollution problem. Ms. Rose though decides to choose one of the gang to stay with her for transformation. Joni decides to stay while the rest of the gang go to stop the pollution problem. Ms. Rose warns them they have a few hours to stop the pollution, and if they don't stop it by then, her army will attack the town. While Santiago goes back up to the surface, Owen, Leslie and LapTrap help fix the pollution problems in each water pipe. As they keep returning to Ms. Rose's throne room, they watch as Joni changes over time. Ms. Rose explains she is transforming as all her captives are and only clean water could save her.
Soon as all the water pipes were not longer bringing in polluted water and started bringing in clean water, the Plant People's kingdom was saved. Ms. Rose thanks the kids for saving her kingdom and she gives Joni back to Owen, Leslie and LapTrap. The Cluefinders' then head back to the surface as Ms. Rose and the rest of the Plant People farewell thanks the kids as the ground closes and the game ends.