Leo Weinbrenner is a man on the verge of being fired - perpetually. In "I Do Over", Leo is about to be laid off from GD, and it's Jack Carter's unpleasant task to break the news to him, in case he 'takes it badly'.
Leo, however, has built his own time loop to prevent the planned dismissal from ever actually taking effect, and everyone else in Eureka is caught up in his little fantasy bubble, which is already malfunctioning.