Tree Estate

Since the Young Six have been given a new home by the remnant consciousness of the Tree of Harmony, the introduction and accommodation of their other friends have started out with arguments and anxiety including Rhabdom having bad memories from being trapped in the Harmony Caves, but the group ends up trapped in the Caves themselves and find out that the Tree of Harmony is dying because King Sombra ensured that it couldn't be restored so easily. Thus their new home, and Twilight's Castle are slowly dying. Thus to escape, they have to save the Tree of Harmony from suffering a worse fate than before, while the Lodgers and Mane heroes try to find them on the surface.