Mainwaring is furious to learn that Wilson is leaving to become manager of the Eastgate branch, where HQ has also appointed him platoon commander with a promotion to Second Lieutenant. While everyone else is congratulatory, Mainwaring's jealous, socially inferior superior implies it's just the old boys network. He promotes Pike to chief clerk, and orders him to copy for all platoon members a promotion to sergeant, meant only for Jones, but so phrased each thinks to get three stripes, creating a Mexican army assembly.
