Plot summary
A combination of Malcolm's disgust at the house falling apart around them, and Hal's fear-induced "zero tolerance" attempts at maintaining peace and order in the family, results in Malcolm being kicked out of the house. The longer he has no home, the more his sanity begins to slip away. Hal finds Malcolm at his ex-girlfriend's house and agrees to keep this between them, knowing that Lois would have gone through greater lengths to find him. At the ranch, Otto's family arrives and Francis has to deal with Otto's piano-playing nephew who intentionally annoys him, which leads to him smashing his piano in front of Otto's family. Reese attaches a fire hose to his back for more speed on his bike, which ends in a disaster.
Credits
Adapted from Wikipedia contributors, Malcolm in the Middle season 4. HTML formatting and reference markers removed.