Michael accidentally runs over Meridith in the parking lot, and his guilt causes him to organize a 5-K run for her. Dwight and Angela have a falling-out after he kills her cat, and the Jim and Pam"s relationship is discovered. Season 4, Episode 2: Dunder Mifflin Infinity Original Air Date—4 October 2007 Michael feels threatened when Ryan returns to the Scranton office to share his ideas about the future of Dunder Mifflin. Jim and Pam"s relationship is shared with the entire office, while Angela and Dwight"s relationship is on the rocks.