The first few seasons revolve around Malcom in his middle school days, which I believe ends in Season 4 when Malcolm goes to High School and has become a depressed emo kid at the Zoo until something (can't remember) changes his mind.
I remember that episode out of all the others.
Sweet. If they're deep enough into the arc they can hear the voice cracks.
Speaking of voice cracks, I think the most voice cracks goes to the episode where Malcolm discovers that his female friend happens to have big, uh,
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s if you catch my drift, and Reese wants to get grabby times with them.