When the late King Sombra was overthrown (and violently exploded), he discovered that there is, indeed, a pony Hell. However, when he is granted an opportunity for redemption, he takes it without second thought. Now, trapped in a game of cat-and-mouse with a mad draconequus and the overlord of Tartarus, Sombra and Discord must rise against the forces of the underworld and claim their freedom...

Or be lost forever in the infernal labyrinth.