The Viper's Nest
Peter Lerangis
 Amy and Dan Cahill are staying inside a small cabin with their uncle, Alistair Oh. However, the evil Isabel Kabra starts a fire in the cabin. Surprisingly, former secret agent and murderer, Irina Spasky, brings them a pole to slide down to safety. Irina climbs to the top and helps them down, but the pole catches fire. Irina senses that the roof will collapse, reflects on her life and decides that she has lived long enough. The roof collapses under her, and she dies. The book begins the morning after the fire that killed Irina Spasky, who was an ex-KGB and Lucian spy. The two were shaken by what had happened, not believing that Irina was on their side, after attempting to kill them earlier in the series. Using their de-coding abilities, Dan and Amy figure that the last words Irina spoke were actually a song: "I'm with you and you're with me and so we are all together", which points them to Pretoria, South Africa. Here, they are given a postcard suggesting a connection with Shaka. 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. They find the clue, aloe, but are captured by the Kabras while leaving South Africa. Isabel Kabra offers Dan and Amy to join their family. When they decline, Isabel orders them to be tied in chairs, and chopped to pieces by a spinning propeller. They escape with the help of Professor Bardsley, together with the vial of green liquid that they thought was their lead to the second clue in The Maze of Bones, by flying Grace Cahill's old plane, The Flying Lemur. During the ride, Dan and Amy accidentally break the vial, spilling some of the contents onto Dan's arm. It turns out to be a Lucian poison. To get the antidote, they fly to Grace Cahill's home in Madagascar. While at Grace's Madagascar home, they find a page in her journal that says, ″I am feeling melancholy today, thinking about my dear A & H and missing them so. 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, along with a piece of music by di Lasso, leads Dan to realize that his and Amy's family branch is the Madrigals.