The Heroes of Olympus: The Mark of Athena (Book 3), Rick Riordan
ANNABETH IS TERRIFIED. Just when she's about to be reunited with Percy, it looks like Camp Jupiter is planning for war. And that's only one of her worries. In her pocket, Annabeth carries a gift from her mother that came with an unnerving command: Follow the Mark of Athena. Avenge me. Annabeth already feels weighed down by the prophecy that will send seven demigods on a quest to find and close-the Doors of Death. Annabeth's biggest fear, though, is that Percy might have changed. What if he's now attached to Roman ways and no longer needs his old friends?
Narrated by four different demigods, The Mark of Athena is an unforgettable journey across land and sea to Rome, where important discoveries, surprising sacrifices, and unspeakable horrors await.
Book THREE: THE MARK OF ATHENA with a true storyteller's sense of pacing, Riordan creates another compelling right down to the cliffhanger at the end.