Description:

Dipper and Mabel's summer, the one that's lasted forever, is finally coming to a close. Or is it?
The Winchester brothers, on the other hand, continue to deal with Lucifer and the apocalypse.

-For Gravity Falls this story takes place after Season 2, episode 15: The Last Mabelcorn.
For Supernatural this story takes place after Season 5, episode 5: Fallen Idols.-

(For those unfamiliar with SPN, there is a video above to help! Sort of.)