Dipper grabs for his copy of Wacky News, one of those supermarket tabloids. It has the usual bullcrap. Twins connected by a beard, a child psychic with very large hair, and something that he shows to his sister.
Mabel: "Human-sized hamster balls? I'm human-sized!"
But what he actually wanted her to see was the advertisement for a monster photo contest.
Dipper: "We didn't get any pictures of those gnomes, did we?"
Mabel: "Nope. Just memories. And this beard hair!"
Dipper: "Why did you save that?"
Speaking of disgusting things, Grunkle Stan comes in wearing only an undershirt and underpants.
Grunkle Stan: "You two know what day it is?"
Dipper: "Um... happy anniversary?"
Mabel: "Mazel tov!"
Grunkle Stan explains what day it actually is while he reaches for the milk.
|That's right, Bessie. Show off that udder. Ooh, you're a naughty cow.|
Grunkle Stan: "You call that Ben Franklin? He looks like a woman!"
And the memory even puts a damper on Mabel's spirits.
Mabel: "The County Jail was so cold...."
But Grunkle Stan promises that things will be different today. Today shall be a day of merriment and mirth.
|This can only end well.|
Dipper: "Grunkle Stan, are you wearing a blindfold?"
Grunkle Stan: "Heh heh. Nah, but with these cataracts I might as well be! ...What is that, a woodpecker?"
But they soon arrive at their destination: Lake Gravity Falls. It's fishing season! And the whole town is out there, including cameos from characters we haven't met yet. One of these is Wendy's dad, Manly Dan Corduroy (John DiMaggio) who doesn't so much "fish" as he does "grabs fish out of the water with his bare hands." Then he does an elbow drop on it for good measure.
Dipper's a bit suspicious of Stan's motivations, but Stan insists that he's just excited to have fishing buddies. The guys up at the lodge won't ever go with him.
Grunkle Stan: "They don't 'like' or 'trust' me."
He hands them over some shoddily hand-stitched hats with "Dippy" and "Mabel" on them, and tries to get them pumped about ten hours of non-stop fishing. And worse than that... he brought the joke book. As the twins try to figure out some kind of way out of this predicament, the local kook, Old Man McGucket (Alex Hirsch, to the surprise of no one) runs around screaming and knocking stuff over.
|Hey, that bald guy looks familiar....|
Mabel: "Awww, he's doing a happy jig!"
Old Man McGucket: "Nooooooo! It's a jig of grave danger!"
Old Man McG's son, Ranger Tate McGucket (Conrad Vernon), comes along to shoo away his crazy dad. Old Man McGucket tries to prove of his claims by showing them his destroyed boat. He claims that the Loch Ness Monstrous beast escaped to yonder Scuttlebutt Island, but the police officers on the scene (Sheriff Blubs and Deputy Durland, played by Kevin Michael Richardson and Keith Ferguson, respectively) aren't impressed.
Sheriff Blubs: "Attention all units. We got ourselves a crazy old man."
|"Y'all may commence laughing as we let the potentially-dangerous, mentally-disturbed man go free."|
Dipper: "Mabel, did you hear what that old dude said?"
Mabel: "Aw, donkey spittle!"
Dipper: "The other thing! About the monster! If we can snag a photo of it, we can split the prize fifty-fifty!"
Mabel: "That's two fifties!"
Mabel imagines using her money to buy a human-sized hamster ball, taking it to town and showing off in front of the teenagers drawn like an 80's cartoon.
Mabel: "You can look... but you can't touch."
|Because there are laws.|
|"You're gonna need a bigger boat."|
Grunkle Stan is left behind in a heartbeat, and he vows to have a good time on his lonesome. Somehow. But after getting halfway there, the S.S. Cool Dude turns around to get sunscreen from the shore, which I'd imagine was a bit awkward if Grunkle Stan hadn't moved out into deeper water yet.
As they finally make their way to Scuttlebutt Island, Dipper gets everybody prepared.
Dipper: "Think. What's the number one problem with most monster hunts?"
Soos: "You're a side character and you die in the first five minutes of the movie. ...Dude, am I a side character? Do you ever think about stuff like that?"
|Whatever gets you through the movie. I mean, day.|
Dipper: "There he is. Bigfoot. Uh oh. No camera! Oh, wait. Here's one. Aww. No film! You see- you see what I'm doing here?"
And so, Dipper has bought seventeen disposable cameras. Four for Mabel, four for Soos, five for Dipper to hold onto, one for under his hat, and three extras. Soos tries out one of the cameras, but ends up flashing his own eyes. He accidentally lets go of the camera and it flies into the water. Then Mabel throws one at a bird that's dive-bombing her.
Dipper: "Okay, guys, I repeat: don't lose your cameras."
Soos: "Wait, lose the cameras?"
Soos: "Dude, I just threw two away."
When all is said and done, they have twelve cameras. Dipper starts assigning jobs, making Mabel the lookout, Soos the helmsman, and himself the captain. And when Mabel throws another camera overboard as leverage, he agrees to let her be the co-captain, which makes Soos ask if he can be associate co-captain, which Mabel authorizes.
Back on task after all the promotions have been handed out like participation trophies, the next step is luring the monster out by dumping massive fish food flakes overboard.
Soos: "Permission to taste some?"
Mabel: "Permission co-granted."
Soos: "Permission associate co-granted."
Dipper and Mabel have a good laugh over Soos's reaction to licking fish food as Grunkle Stan watches from afar, vowing to get revenge. And since living well is the best revenge, he goes to find new fishing buddies.
Out in Lake Gravity Falls, a young man named Reginald is out with his sweetheart, Rosanne, preparing to ask her the big question. But before he can present the ring, Grunkle Stan interrupts to make friends the only way he knows how.
Grunkle Stan: "Wanna hear a joke?"
Grunkle Stan: "Here goes. My ex-wife still misses me... but her aim is getting better! ...Her aim is getting better! You see, it's- it's funny because marriage is terrible!"
Number 85 on the list of things you don't expect to hear in a Disney show, right after "That's what she said!"
As the fog rolls in during the approach to Scuttlebutt Island, Mabel keeps herself occupied by using a pelican as a ventriloquist dummy. Dipper reminds her that she should be keeping a lookout for shore, and she does. She watches the boat smack right into it. As they venture forth through the forests of Scuttlebutt Island, Soos does what anybody would do when confronted with a sign that says "Scuttlebutt Island."
|Keep it classy, Soos.|
Now, there's a semi-memetic picture going around of this scene because Slender Man's in the background! ...Except he's totally not. Here's the undoctored version of the image making the rounds.
|Sorry, everybody. Looks like you'll just have to wait until Dipper starts looking for the Hide-Behind.|
Mabel: "So majestic...."
When a possum steals their lantern, Soos suggests that perhaps this endeavor isn't worth it. But Dipper's fantasy sequence says otherwise. So forward they go, with Mabel rapping to Soos's beatboxing to pass the time.
Mabel: "My name is Mabel; it rhymes with table! It also rhymes with glable! It also rhymes with shmabel!"
Soos: "Dude, we should be writing this down."
But more strange noises happen. Venturing forward, they find... beavers. And they're cavorting in that way beavers do.
|Beaver-on-beaver action! ...Okay, honestly, I didn't realize how that sounded until I already typed it.|
|"My God. I am become Gideon, feller of trees."|
Sequel to Hobo with a Shotgun.
Over with Grunkle Stan, he's teaching some random kid about knots, to the understandable alarm of his parents.
As Soos takes some glamour shots of a beaver, Dipper starts feeling remorse over ditching Grunkle Stan over nothing. Then... the Gobblewonker appears.
|Way to stay on top of things, Dipper.|
Meanwhile, Grunkle Stan glares at an old man in a nearby boat, having a lovely fishing trip with his grandchildren, Shmipper and Shmabble.
Shmipper: "Pop-pop... I just weawized dat... I wuv you."
Grunkle Stan straight-up start booing this tender display, angering Pop-pop. But the kids get him to understand the situation.
Shmipper: "Maybe he has no one who wuvs him, Pop-pop."
Before Stan can yell his rebuttal, Soos zips by, followed by the Gobblewonker. After all sorts of hijinks ensue, the chase ends when the boat crashes into the eponymous falls of Gravity Falls, finding a secret cave. The Gobblewonker follows, but gets stuck in the entrance. And with the camera that Mabel reminds Dipper is under his hat, he manages to get some awesome pictures.
But a stalactite hits the beast, breaking it and making it spark. Dipper investigates and finds that it's just as solid and metallic as that tree by the Mystery Shack. He finds a hatch and opens it. Inside, he doesn't find the Mad Scientist's Club, but Old Man McGucket!
Old Man McGucket: "Well, when you get to be an old fella like me, nobody pays any attention to you anymore."
He figured that if his own son won't come visit, then a killer robot would solve the problem!
Old Man McGucket: "In retrospect, it seems a bit contrived."
But Old Man McG's words about old-timers just wanting to spend time with their family hits home for Dipper and Mabel.
Soos: "Dude. I guess the real lake monster is you two. Heh heh. Sorry, it just, like, boom, just popped into my head there."
McGucket explains that his first instinct was to build the robot because he's built a lot of robots in his day, including a couple that terrorized the town. I wonder why nobody in town remembers this.... Oh, well. McGucket gets back to work on his death ray, and the twins hurry back to spend the rest of the day with their Grunkle Stan, using their last camera to document Family Fun Day. Grunkle Stan claims that he had a great time without them, though.
Grunkle Stan: "Making friends, talking to my reflection... I had a run in with the lake police. Guess I gotta wear this ankle bracelet now, so that'll be fun."
But he quickly softens and the rest of the day is well spent.
Grunkle Stan: "You knuckleheads ever see me thread a hook with my eyes closed?"
Dipper: "Five bucks says you can't do it!"
Grunkle Stan: "You're on!"
Mabel: "Five more bucks says you can't do it with your eyes closed plus me singing at the top of my lungs!"
Grunkle Stan: "I like those odds!"
After a montage of the rest of their day shown in photos, complete with another run-in with the cops, the credits roll.... as some mysterious Gobblewonker-esque shadow actually lurks in the deep.
This time, the credits try to distract us from the code with more of Mabel's pelican ventriloquism. The translation: "Next week: Return to Butt Island."
And so, the episode ends. Now let's review.