When the gang visit a town, they realize strange things happening.
- Scooby-Doo (Frank Welker)
- Shaggy Rogers (Matthew Lillard) - he and Scooby act like high school jocks during their mysteries
- Fred Jones (Frank Welker) - refered to as an idiot by Agent Cranston.
- Daphne Blake (Grey DeLisle) - gets a makeover similar to Jean Grey's style in X-Men: Evolution.
- Velma Dinkley (Mindy Cohn) - loosing her mind trying to solve the Remote control, but temporary.
- Greer Danish (Sirenia Irwin) - the mayor of her hometown on a Election Day, who seeks from Mystery Inc.
- Amuk (Stacey Keach) - the demon from the Underworld, he somehow terrorizes the town, Dume.
- Jack Curtis (Gary Cole) - a doctor, Reason: he and Vincent were spied on by Fred, Daphne and Velma doing a ritual, and then was captured and asked why, he reveals, that they fell for superstitions, and were out of their minds.
- Vincent Rule (Stephen Root) - Reason: was performing a ritual with Jack
- Wayne Gross (Crispin Freeman) - a school jock who meets Shaggy, mistaken as a jock, and Scooby, mistaken as a mascot for "Gaydenberg", Reason: Shaggy and Scooby hear him and his friends are going "Out tonight".
- Fiona Lee (Caitlynne Medrick) - has the same tone as Total Drama's Dawn, Reason: she vanishes, floats in thin air, cares for Mother Nature, and she moved from a wet spot to a dry spot
- Agent Cranston Carnaby (Alan Tudyk) - an FBI agent, who does his job, and warns Mystery Inc to stay off the FBI's back, has the same tone as Agent Steven Fullbright from Beverly Hills Cop 3, Reason: tells Shaggy and Scooby warningly that he and the FBI need to the job alone, and tells them to stay off their backs
1. Log Book that keeps track of the Towns Ritual Ceremonys.
2. Sun-Glasses that had broken Fragments at the Carnival Ride.
3. Remote Control that is used for the ferris ride.
1. Agent Cranston Carnaby (Alan Tudyk) - who was using the Amuk ruse to scare people off the Carnival grounds, so that he can have an excuse to use his badge on the townsfolk.
2. Greer Danish (Sirenia Irwin) - wanted to make the Scooby Doo gang look like they are not doing their jobs, so she could be elected Mayor.
In Dume a town where Classic stories even the Reinassance Festival is being held, There Jack Curtis, and Vincent did a Magic ritual for the opening, and unwittiedly released Amuk, a Demon Sorcerer who desired to take the whole town, and make it into his own ways, and his own hours, and nothing will stand in his way.
On the Road Scooby Doo, and the Mystery Inc gang tries to head toward Main Rd. to get to the Renaissance Festival. Scooby brought out his Jester outfit, and Shaggy brought out his magician outfit. Scooby sees that Velma is wearing the Princess outfit from online she was going gaga over, Fred is wearing a Viking outfit similar to Beowulf's, and Daphne is weairing the Elf costume from Zak and Daxter. As they arrived the mayor, Greer Danish asks that they could help.
At night, the gang start the mystery by splitting up, Shaggy and Scooby head to the high school, while Fred, Daphne and Velma go find history about Amuk.
Meanwhile Velma is searching the history of Amuk, and found that he was a sorceror who was messing with Medieval enchantments, Velma was shocked to see that There is no evidence that of his death, nor of how he became a monster.
Shaggy and Scooby are looking for clues, when suddenly, they meet Wayne Gross, who tells them that they must be apart of the football team, Shaggy as a jock, and Scooby as a mascot for Gaydensberg, and they start training.
Fred and Daphne are alone, they talked about marriage, when suddenly, they spied on a girl named Fiona Lee, who asks for their support for Mother Nature to live again, Fred and Daphne sign, until suddenly, they find that Fiona has disappeared, which makes them believe her to be a suspect, Velma comes by and tells them about Amuk, then they went to spy on Jack Curtis and Vincent, who are performing an ancient ritual, Jack goes out, and Fred, Daphne and Velma grapple him.
Later, Shaggy and Scooby hit the showers after training, Wayne Gross tells them that they're going "out tonight", Shaggy and Scooby ask if they can come along, Wayne says yes, and knock themselves out, then they got dressed.
Meanwhile, Jack wakes up to see Fred, Daphne, Velma and Greer confront and ask him about Amuk, Jack said that he and Vincent fell for superstitions and were out of their minds, Fred, Daphne and Velma look at each other, and allow Greer to have security watch him.
Later, Shaggy and Scooby are with Wayne and his friends, as they are trying to cause a prank on the school property, and as Shaggy was caught by the police, Wayne tried to explain it was their fault, and not theirs.
Shaggy and Scooby are in jail, but are released and need to be worded with Agent Carnaby in his office, Carnaby speaks with them, says, "You and the gang are amazing, you do well in solving mysteries, you are......Outragious", Shaggy and Scooby gulp, "we need you and your gang off our backs, we can handle this, do you 2 clowns, copy me?", Shaggy and Scooby nod, "Like, yeah, we copy ya, come on, Scoob", they are stopped, later, with Carnaby giving them pass tickets, "5 passes for Mystery Inc., back to Coolsville they go", Shaggy and Scooby take them, scared.
Then, they met up with the gang about some suspects, Fred and Daphne discuss about Fiona Lee and Jack and Vincent, Shaggy and Scooby discuss about Wayne Gross, and Carnaby was scaring them with a deep tone, These were the only 5 suspects they have.
Scooby and Shaggy went back to the Mystery Machine and realizes that Velma has just lost her mind, and just was going insane, Scooby grabs a bucket of Water to snap her out of it, they tell a sane Velma about Carnaby, and Wayne.
Daphne was asleep and has a nightmare of marriage, in the nightmare there was an impregnation transformation, and Daphne was seen as an milf, and is scared of not being a better parent, Fred wakes her up, and tells her "it's gonna be alright, Marriage is the first step, your just getting ahead"!
Amuk attacks the Scooby Doo gang at the castle attraction, and attacks Fred, and Fred punches him infront of the audiance to expose Carnaby Cranston as Amuk, and that he did it to get the gang off his back, and as an excuse to use his badge on the citizens. Wayne apologized to Shaggy for getting them into that practical joke, Daphne is seen to gain a makeover during the whole time, and states "Fred, the 70's is over, try a new age design"!
Velma is still not convinced that Cranston did all that alone, until she found a book at Greer's apartment, about Amuk's design, and the fabrications are just like the robe on Amuk, and a book that has magic properties. Velma realizes that Greer and Cranston were together the whole time, Velma also realizes when she enters Greers room, behind the door, that she was wearing a wig to show it is shorter than it really was, she was wearing fake glasses, removes her shoes to expose the same paint that was on Amuk's makeup, Velma sees on the walls shows she is actually 29 years old, and is actually running for Mayor. Greer reveals that she is actually a swimsuit model, and has tattoos on her back that is the same Dragon symbol that was on Amuk's flag. Daphne was behind Velma, and was also shocked atcually stated "Velma,Greer and I have something in common", Velma was wondering about having a beautiful body, was like saying save it, Greer than removed her teen look mask, to reveal as a red liped, and very smoking hot woman, Velma remembered the picture of the maiden realizing that Amuk, was actually an act and was mistaken for a real monster.
Daphne and Velma inform Fred, Shaggy, and Velma of their discovery that Greer was behind the whole shing dig, Wayne informed them about Greers true colors that she was going to be elected, but lost to Wayne's dad, and Curtis was a nomanee, which explains why Cranston was hired by Greer. Daphne notices that Velma decided to have a makeover like Daphne did, and it's scientifical.
as they were gonna arrest Greer, they realized she was transformed into a Black Dragon by Dark Magic from the Amuk Book, and Velma actually plans to stop Greer from destroying the town, by making the biggest trap in the world, and Wayne, Jack. and Vincent helps out, and they find Fiona trapped in a tower, and Velma frees her and tells her how to stop her, Velma finds some mold that was glowiing, and spread it on the cage, and has commit it, to the Dragon, and it was captured, altough they couldn't change Greer back, she still retains her personality, and apologizes for her actions.
Fred and the gang enjoy their time in the festival and the Carnival, and Jack was made mayor, Cranston was fired from the FBI, and was made the fool of the Festival, and Greer as a Dragon had made a better attraction at the festival, Jack was made Mayor, and promotes Vincent as Deputy, and Wayne makes a mystery club in honor of the Mystery inc Gang, Fred states "We aren't kids anymore it's the dawn of a new age"!.
Scooby: "Scooby Dooby DOOOOO!"