Mabel and Dipper are sent to live with their grunkle for the summer. Stan made Dipper do the most dangerous jobs. One say when he couldn't decide which was worse he picked randomly, ending up picking Mabel.
She ends up finding a weird metal tree and a book. Dipper ran into her, he went to check on pher as he was worried for her safety. Just a half hour later she meets a guy who Dipper justifiably thinks is a zombie.
But later she finds out...the disappointing truth. When Dipper shows up they run for their lives. Mabel "They're catching up to us" Dipper "Oh really. Didn't notice"
When backed up they remember how weak they were before they grouped up and used the leaf blower to seperate them.
The two hug and go in. Both take something. Then Mabel plays with her grappling hook all night without sleeping.