When Mr. Burns gets sick, only a transfusion of Bart's blood, which is a special type, can save him. With the boy's blood coursing through his veins, Mr. Burns is more alive than ever and writes a thank-you note to Bart. Homer is convinced that Burns has not shown his boy enough gratitude and writes his boss a nasty letter. Realizing he's made a mistake, Homer tries repeatedly to stop Burns from getting the note, but can't do it in time.

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