Dr. Weird starts saying "Gentlemen... Behold! My time-space conti..." and he suddenly freezes. Then a surprised Steve takes a closer look and drops him into the floor which causes Dr. Weird to break into several pieces. Then Steve leaves in a nervous haste.
Master Shake destroys Meatwad's dolls with a lawnmower and Frylock promises to buy him a new one. Meatwad wants a "Jiggle Billy" doll, which costs $149.95 and comes with night-vision goggles. Frylock doesn't want to spend that kind of money on a new doll and instead buys Meatwad a "Happy Time Harry" doll, which only costs $3.99 and comes with "real dancing glitter shoes."
As soon as Meatwad takes Happy Time Harry out of the box, it becomes clear that Harry isn't all he's cracked up to be. Instead of being happy, Harry is very depressed. He has bills and child support to pay, and he needs money. He also has an addiction to pills and an alcohol problem. His problems are all real, although Frylock refuses to believe them and gives Meatwad phony money and fake prescriptions. Meatwad finally lashes out at him for what he's putting Harry through and Frylock angrily vows to get Meatwad a new doll.
Harry is not just depressed but suicidal, and he cuts himself. Shake decides to torture Meatwad by attempting to destroy yet another one of his dolls with a blowtorch. Meatwad, affected by Happy Time Harry, is unfazed by Shake's bullying and tells Shake to get it over with. Shake continues to bully Meatwad while Harry douses himself with gasoline and orders Shake to burn him. Shocked at what he's seen, Shake runs inside to "go pray".
Frylock returns from the toy store with the Jiggle Billy doll Meatwad originally wanted and Jiggle Billy wants to have fun. However, Happy Time Harry has an effect on him as well and Jiggle Billy becomes depressed. Jiggle takes his gun and shoots his own head off. Frylock sees what Harry has caused and threatens to shoot him with Jiggle Billy's gun, but Shake decides that Harry must become "immortal".
To this effect, the Aqua Teens go to a cliff where Shake will throw Happy Time Harry off in order to make him a Highlander, like in the film and television series. Harry, however, already knows that "Highlander" is fictional and after Shake confuses it with "Braveheart", Harry again corrects him. Unamused with being shown up, Shake chucks Harry off of the cliff. Inexplicably, Shake goes down the cliff after him wanting to be a Highlander too. After briefly catching his straw on a hanging branch, the branch gives way and Shake falls down the remainder of the way.
A few weeks later Shake has partially recovered from his injuries and heads to Carl's backyard in a wheelchair with a pair of glass eyes. Frylock and Meatwad are speechless. Shake is brandishing a sword and lifts in into the air, claiming "there can be only one!" The sword is then struck by lightning and Shake falls out of the chair and bursts into flames.
- Shake makes a reference to the film Braveheart when he says "There's magic cliffs everywhere. And Mel Gibson!"
- Frylock tells Meatwad to flip Happy Time Harry over because "that's how Hendrix died," alluding to guitarist Jimi Hendrix who choked on his own vomit from drug overdose.
- A number of references are made throughout the episode to the Highlander films and Highlander the television series.
- Normally, Vanessa has hair and a moustache, but in this episode, they both disappear.
- When Shake is on fire after being struck by lightning, if you look closely you can see that the fire has logs edited out of it.
- While Meatwad and Frylock are shopping at the store, there is elevator music playing in the background. This song is "Sunday Will Never Be The Same" by Spanky and Our Gang, a group of the 1960's.
- This is the first episode that Carl doesn't make an appearance in.