Two years after the bachelor party in Las Vegas, Phil, Stu, Alan, and Doug jet to Thailand for Stu's wedding. Stu's plan for a subdued pre-wedding brunch, however, goes seriously awry.

One magical day, June is running through the woods to find her way home where she discovers an old rollercoaster car and climbs inside. She suddenly finds herself in Wonderland, an amusement park she had created in her mind and put aside. All of her rides and characters are brought to life but are falling into disarray without her. Now, with the help of her fun and lovable park characters, June will have to put the wonder back in Wonderland before...

With hundreds of cases solved and adventures shared, Scooby and the gang face their biggest, most challenging mystery ever. Discovering that Scooby has a secret legacy and epic destiny, Shaggy remembers how he met the puppy and how Mystery, Inc. was formed.