Alice-Miranda and Millie have made a dazzling discovery in the woodlands near their school. They vow to keep the secret to themselves, but it seems that a greedy politician and a pair of old friends are searching for the same treasure.

Back at school, the sixth grade girls are preparing for a change to high school. Jacinta is being particularly grumpy with everyone and even with the most persistent questioning, no one quite knows why.

When Myrtle Parker's husband awakes from his coma and disappears, Alice-Miranda puts on her detective hat. She's determined to find Reginald Parker, deter the politician and uncover exactly why Jacinta is playing up.