After the funeral of Grace Cahill, siblings Amy and Dan learn that her will offers a choice: take one million dollars or pursue the first of thirty-nine clues scattered around the world. They choose the clue and enter a dangerous race against rival relatives to uncover the source of power within the Cahill family and what happened to their parents. Based on the opening adventure in The 39 Clues by Rick Riordan, this graphic novel is adapted and illustrated by Ethan Young.