Joan Lowery Nixon

When they are left with a mysterious, witchlike babysitter on Halloween, Susan and Mike try to figure out whether she really has magical powers.

Susan and Mike use their detective skills to figure out what happened to the missing ingredients for their New Year's party refreshments.

Shirley and Claude lead a settled life with their adopted son, Tom, until Shirley goes to town to retrieve Tom's sister, Bessie, and the two run into more than their share of trouble with criminals.

Amateur detectives Susan and Mike track down the mysterious sender of an unsigned valentine.

When Susan and Mike think they overhear thieves plotting the theft of a valuable Easter egg, they organize their neighbors to ward off the crooks.