The 39 Clues series is intended for children aged 8–12, and takes the form of a multimedia adventure story spanning 10 books.

The book begins the morning after the fire that killed Irina Spasky, who was an ex-KGB and Lucian spy.

The two kids are shaken by what had happened, not believing that Irina was on their side, after attempting to kill them earlier in the series.

Using their decoding abilities, Dan and Amy figure out that the words are actually a song, which points them to Pretoria, South Africa.

As they unravel the history of Shaka, they find out that he was a member of the Tomas branch, and was connected to Winston Churchill.

I cannot even bear to listen to my beloved di Lasso, because of the reminder...″, and on another page it says, ″I have written Deng Xiaoping, who has agreed to grant to visit to A & H when he discovered that they, like him, are "M." This leads Dan to realize with horror that his and Amy's family branch are the Madrigals.