Cam Jansen and the Mystery of the Stolen Diamonds

Cam Jansen and the Mystery of the Stolen Diamonds is a 1980 young reader’s chapter book by American author David A. Adler. In the story, Cam Jansen and her best friend Eric are shopping at the mall when they witness a commotion at Parker’s Jewelry Store. As the two friends watch people leave the store, Cam uses her photographic memory to take mental pictures of the scene. When the police are stumped by the robbers’ tricks, she and Eric must use teamwork and critical thinking to analyze the clues and solve the mystery. 

This guide refers to the Kindle edition.

Plot Summary

In Chapter 1, Cam and her friend Eric are at the shopping mall when they notice a commotion in Parker’s Jewelry Store. When a mustached man in a dark suit rushes out of the store and dashes through the crowds, Cam takes a mental “photo” of him with her photographic memory. In Chapter 2, Cam and Eric continue to watch the store and soon notice a strange couple with a baby emerge. The kids watch with interest as the police arrive. In Chapter 3, Cam and Eric ask two witnesses what they saw in the store. The witnesses reveal that a man robbed Mr. Parker, the jewelry store owner, demanding all the store’s loose diamonds. The kids are amazed when the police find and arrest the mustached man in the dark suit, but the witnesses tell them that this man is not the one who held Mr. Parker at gunpoint.

In Chapter 4, the kids discuss the strange couple and wonder why the pair had no real baby supplies other than a large rattle. They watch as the arrested man is released. Then they puzzle over the reason why he leaves the mall in a different direction than before. Suspicious, they decide to follow him.

In Chapter 5, Cam, Eric and baby Howie follow the man from a distance as he walks away from the mall and heads down a road of abandoned houses. When he enters a house, they watch through the window as he meets up with the strange couple from the store. Cam tells Eric to get the police while she waits at the house and keeps a watch on the suspects. In Chapter 6, the mustached man emerges from the house and catches Cam and baby Howie, bringing them inside. Cam watches as the thieves take the stolen diamonds from the baby rattle, and she realizes that their “baby” was actually a doll. Feeling scared, Cam creates a distraction and finds a hiding spot.

In Chapter 7, Cam hides from the thieves behind a bookcase and is relieved when a police officer comes to her rescue. The police surround the house and arrest the thieves. In Chapter 8, the police help Cam, Eric, and baby Howie to return to the mall, where they reunite with Eric’s mom. The police officer thanks Cam for her detective work and praises her good memory. The police admit that the robbers’ trick nearly worked, and they announce that Cam and Eric are heroes for cracking the case.