In their latest adventure, the four Alden siblings are in central Oregon, spending a week with a friend of Grandfather's. Victor has two adult daughters: Marianella volunteers with a search-and-rescue dog team, and Adelita is a pilot. Marianella offers to let the children accompany her on a search-and-rescue training session. While they are walking through the Cascade foothills, they find a yellow backpack from Twila's Handcrafted Jewelry Creations filled with valuable jewelry. When they return the backpack to the local jeweler, Twila tells them that a very special necklace is missing from the bag. She blames Adelita, who was supposed to fly the bag to a customer. There is no sign of Adelita initially, but the children later learn that after she realized her baggage compartment had opened during the flight, she hiked through the area, trying to locate the missing items. Aided by their dog Patch, the children follow a series of clues to the culprit responsible for the missing necklace. While this entry follows the same light tone as the other titles in the series, it suffers from an ethical flaw: it is troubling that Twila faces no repercussions after wrongfully accusing an innocent person and attempting insurance fraud. Still, this omission seems to go over the heads of Henry, Jessie, Violet, and Benny, and perhaps it will not bother the young fans of the series. Reviewer: Kim Dare