This crossover episode will air as the premiere of Family Guy’s 13th season in September. The Griffins somehow end up in Springfield where The Simpsons live; Peter Griffin and Homer Simpson bond over donuts and beer until they have a falling out and re-create Family Guy's famous chicken fight scene (more on this below). Bart, as you can imagine, makes an excellent mentor for Stewie.
“This Springfield place seems nice. We should visit here again,” Lois Griffin says in the preview. “I don’t know, Lois,” Brian responds. “It kind of feels like a one-shot deal.”