Release Message: On April Fool's Day, Jules and Verne "sabotage" many of Doc (Dan Castellaneta)'s inventions, including his Brain Wave Analyzer.
Description: On April Fool's Day, Jules and Verne "sabotage" many of Doc's inventions, including his Brain Wave Analyzer. After using the tampered machine, Doc thinks he has used up 99.99% of his brain and retires from science. After many attempts at seeking other employment (parking cars, mowing lawns, making pizzas), he goes back in time to the Cro-Magnon period. Realizing that there are still things left to invent (the wheel, etc...), he decides to go to Marty's rock and roll concert Ð it is something totally mindless. Marty has "borrowed" one of Doc's tampered inventions Ð the Environmental Adjuster Ð to create special effects for the concert and in doing so, creates a catastrophic rainstorm/flood. After accidentally tearing up the curtain, when Marty lands into the water along with Jules and Verne, it is up to Doc to use his remaining .01% " of his brain to get everyone out of danger. The boys confess to their pranks and the inventor returns to his life of science. Issue 4 of the Back to the Future comics is an adaptation of this episode.