Infinity Train GF: Star's Vanish (Gravity Falls Infinity Train Crossover)

In their first summer in Gravity Falls, Mabel Pines had her moments, but to be honest she's been a bit self-centered. Her twin brother, Dipper, has done so much for her and she's hardly returned the favor. Even after going to Gravity Falls, Mabel hasn't learned her lesson and has become more selfish then ever. She dem...