Sammy continues to make life with her grandmother interesting as she tries to discover who is stealing from St. Mary's church, befriends a homeless girl, and plays in a softball tournament against a bitter rival.

When cats begin to mysteriously disappear in Santa Martina, thirteen-year-old friends Sammy and Holly start snooping around town to find out what is happening.

When her history teacher begins receiving death threats and her own name is near the top of the suspect list, eighth-grader Sammy is determined to find the real perpetrator, but she is distracted by her mother's relationship problems, her almost-boyfriend inexplicably avoiding her, and her duties as a reluctant bridesmaid.

After a dog she is watching disappears from a city parade and the owner receives a ransom note, thirteen-year-old Sammy must use her detective skills to solve the mystery.

Thirteen-year-old Sammy's penchant for speaking her mind gets her in trouble when she involves herself in the investigation of a robbery at the "seedy" hotel across the street from the seniors' building where she is living with her grandmother.

When Justice Jack, a self-appointed superhero, begins trying to track down the missing Mrs. Wedgewod and some stolen cash, the older folks in Santa Martina are delighted but Sammy knows it will be up to her to really solve the mystery.