It started by the death of Grace Cahill (A really graceful figure no doubt), with a strange will. Either take 1 million dollar or a mere clue; might lead to unlimited source of power. Most of the heirs was smart enough to take the million dollar fortune and be happy. But these two kids; Amy and Dan, planned to make their Granny (deceased) proud. So they burned 2 million dollars and took the clue. Along with six other competitive teams, they set on the quest to find the 39 clues. After that, events started unfolding with an unusual manner. Before they knew it, they had been attempted to killed three times, wandering in Paris, and knowing nothing about what to do next.
The story was full of suspense, even at the end you will be tempted to just turn the page and read the next one. I can't wait to buy the second books of the series.
If you love puzzles (like me), this is just the book for you. I highly recommend it!