Complex sentence: But when the Mayor himself rebukes him, calling Terry a drunk, Jimmy promptly sneaks into the mayor's office and pastes the letters all over the walls of the Mayor's office while security is diverted by a fire set in a nearby office bathroom.
Split into simpler sentences: But when the Mayor himself rebukes him, calling Terry a drunk, Jimmy promptly sneaks into the mayor's office and pastes the letters all over the walls of the Mayor's office. Security was diverted by a fire set in a nearby office bathroom.