Ok, so, things got (marginally) more serious.
Why does Lil Gideon want the Mystery Shack so badly? And why does he think simply having the deed will do that? Stan needs to, like, sign it over. Physically holding the thing means squat.
Fortunately for Gideon, no one else seems to realize that either.
I am getting ahead of myself. Gideon wants to build a special tent atop the Shack, but the only thing standing in his way is Stan’s safe with a combination that only exists in Stan’s head. Gideon does have the #2 journal, and there is a system of nearly last resort to get information from someone’s mind. That means conjuring a powerful demon named Bill Cypher, a one-eyed pyramid with a top hat. Mabel and Soos saw the conjuring, and Bill will help Gideon for a favor he wants in return, though he never says what that is.
As it is, Dipper knows that name. Journal #3 says to never, ever, ever conjure Bill Cypher. That would be BAD. And then Bill enters Grunkle Stan’s sleeping mind. It’s a good thing Dipper’s book has a means to follow Bill, so he, Mabel, and Soos go in. Sure, Dipper wants to know why Stan keeps picking on him, but that can wait.
Bill is actually pretty dangerous, but there are a lot of doors in the memory wing of Stan’s mind, and that means checking a lot of them. Dipper finds one where Stan confides in Soos that Dipper is a weak loser. That sucks. But when Mabel, Soos, and a pair of fictional idiots that Mabel has a crush on find the door, a second Soos steps out and, well, the first Soos was Bill and he has the right door, and only quick thinking from Mabel prevents Bill from getting the combination to Gideon, who promptly breaks off the deal to go with an even more final plan. That makes Bill mad. He gets very scary when he’s mad.
Where was Dipper? Overhearing the rest of that conversation. Stan doesn’t hate Dipper. He loves Dipper. He sees himself in Dipper and wants to toughen the boy up so he can defend himself when he needs to. And when Dipper falls into the memory, Memory Stan tells Dipper that, you know, in someone’s mind, you can do whatever you want. That means Soos and the twins can fight off Bill and he’ll leave because he just knows he’ll be back.
Considering Soos found, and opted to ignore, a memory of Stan going into a secret door behind the vending machine, this episode is clearly setting things up for the future.
Like how this one ended with “to be continued” after Gideon used dynamite to blow the safe and get that deed.
Again, I don’t think it works that way.