Talia's warrior instincts kick into high gear when an old enemy appears with a one-time offer. The whole Mexico Expedition goes into lockdown after a terrifying betrayal and a violent attack. A crushing mishap may end any hope of unraveling the tangled Web of Araña. Students respond to "activation orders' with turmoil and terror. One conflicted father may hold the key to understanding more about the enemy — if he lives to tell his tale.