While Ward (Hugh Beaumont) is on a business trip to St. Louis, Wally (Tony Dow) has been appointed "substitute father" to brother Beaver (Jerry Mathers). Soon afterward, Beaver gets into trouble by using (gasp!) bad language in school, whereupon Miss Landers (Sue Randall) demands a meeting with our hero's parents. Thus it is that Wally makes a game effort to pass himself off as "Mr. Cleaver" -- with the expected results. This is the final episode of Leave It to Beaver's fourth season, and the last in which Sue Randall appears as Beav's teacher (though she'll return for a cameo appearance the following year). ~ Hal Erickson, Rovi