Henry, Jessie, Violet, and Benny Alden, the Boxcar Children, are going gem-hunting.
Jessie finds a stunning ruby in the annual Ruby Hollow Gem Mine competition, but before she can enter it in the competition, it disappears Has she just lost it, or did someone take it? Now, instead of digging for gems, the children dig for clues. Who wants to win so much that they'd steal from the children? The Boxcar children are determined to find out.
