Homer and Marge have set an ultimatum for Bart and Lisa: if they can get above a C-average in each of their school course, they can go to Kamp Krusty.
Lisa's report card is perfect (with the exception of a 'B' in conduct), but Bart's grades are in the D-range. Bart attempts to plead with Mrs Krabappel and fix his grade, but this does not work. Even so, Homer lets Bart go, simply on the grounds of not wanting to put up with him all summer long.
Arriving at Kamp Krusty, the kids are informed that Krusty the Clown will be coming in the next few days, but until then, a straight-laced man in a suit named Mr Black will be in charge. Mr Black enlists Dolf, Kearney and Jimbo to enforce law in the camp, usually bullying and chastising the campers.
The facilities are a nightmare, the kids are served Krusty-brand imitation gruel, and forced to make imitation Gucci wallets in 'arts and crafts.' Lisa manages to send a letter to Homer and Marge detailing the terrible conditions, but the two simply think she's exaggerating. In the meantime, without Bart and Lisa, Homer has grown new hair and lost weight, and has rekindled his love life with Marge.
Eventually, Mr Black says that Krusty has arrived, but it turns out to just be Barney Gumbel in a bad Krusty suit. Finally pushed to his breaking point, Bart encourages the kids to rebel, taking over the camp and sending Mr Black and his cronies running.
Eventually, the news of the camp takeover reaches Krusty, who has been spending his time in England. Coming to the camp, Bart outlines what happened, and Krusty promises to make it up to the kids...by taking them all to Tijuana for 2 weeks!