The 39 Clues - Supplementary Works

Supplementary Works

Scholastic has expanded the 39 Clues universe with several books. In 2010, Scholastic published Agent Handbook, which explores the techniques that the clue hunters in the series use to find clues, and The Black Book of Buried Secrets, which provides more information about events in the series. On the last week of December 2011, the Scholastic editorial team released seven short stories as part of The 39 Clues: Rapid Fire e-book series. The editorial team has also released The Cahill Files, which includes Operation Trinity, Spymasters, and three e-books. As part of the multimedia interactive experience to promote the series, Scholastic includes six cards in each book of the 39 Clues series. Each card unlocks one online clue, which readers can unlock by entering the code on the cards on their 39 Clues account online.