Herman is taking a correspondence course (sent from Tijuana!) on "Learning How To Be A Dectective" and has been out the last three nights with the goal of "making the streets safe for women and children." Of course, he doesn't tell anyone until finally he mentions it to Grandpa. The rest of the family is in the dark but they know he's not coming home until 11 each night and has some lame excuse each time.
Herman's idea is to give up his job for this "high-paying job in the career of law enforcement." That's why he's been out the last three nights: practicing how to shadow people. Grandpa thinks he's nuts and reminds Herman is "a big shot down at the parlor." He also reminds him Lily won't go for this....but you know, Herman: once his pea-brained mind is set on something, he goes for it....until he totally bungles things.
Anyway, the real fun starts the next night when Herman goes back out. We see him discussed as a statue as a pilgrim; then snooping under a bush dressed as Sherlock Holmes, and then interrupting two teens kissing with his Charlie Chan "number one detective" outfit.....all very funny scenes.
Lily checks up on him and finds out he's not working overtime, so she hires a detective to have followed. The agency puts Herman on the case: to follow himself, as it turns out! Weird!
Not a lot happens in here but when it does, like the above scene, or when Herman gets an assignment to guard a married woman, the results funny.
