The episode begins with Malcolm frantically running to get to class since he is running late. When he arrives he is surprised to find the classroom is empty and the only one there is the teacher, Charisse. Charisse informs him that today was ditch day, Malcolm tells her no one told him about a ditch day, she is surprised since she saw everyone of the students telling all their friends. Malcolm is shocked, then another teacher named Val comes in with a large bottle of alcohol, he asks Charisse about Malcolm and is stopped giving him a drink, although he may need it.
After Hal forbids Dewey from inviting his peculiar classmate Chad over for a sleepover, Dewey asks Lois instead. Lois searches for the warranty papers on her 10-year-old blender that she wishes to return for minor infractions. As she searches for it, Chad places an envelope at the end of Lois' papers containing a pornographic photo of a sleeping Lois taken by a drunk Hal.
Meanwhile, Malcolm and Reese find out that they are not as popular as they once thought (because there was a Ditch Day, and no one told them), then plot "revenge" on their classmates. When they confront their classmates, Malcolm and Reese are in for a surprise. It's revealed the main reason why the students never told them about Ditch Day was because they were obviously still angered over Malcolm and Reese getting them arrested in an earlier episode.
Hal gives Chad a book with a highlighter to write in, but his obsessive-compulsive disorder leads Chad to inadvertently revealing the pornographic picture to Lois. Lois comes in the boys' room to confront him for taking a pornographic picture of her.
Malcom and Reese come home and bond once more over it.
- Chad and Hal are revealed to have O.C.D., with Hal having a far more minor version of it.
- Patrick Bristow, the actor who played Lloyd (Chad's father), previously played the role of a background character in Otto's murder mystery weekend at The Grotto.
- Although it's not explicitly revealed, the students resent Malcolm and Reese for getting them arrested from a previous party they invited the two to in Lois' Sister