The Mark of Athena is the third installment in the Heroes of Olympus series by Rick Riordan. The book follows the lives of seven demigods Percy(son of Poseidon), Annabeth( daughter of Athena), Jason(son of Jupiter), Piper(daughter of Aphrodite), Leo(son of Hephaestus), Hazel(daughter of Pluto) and Frank(son of Mars). They are a group chosen by Hera to go to the Doors of Death and the stop the giant amy from overthrowing the Olympian Gods. While on their quest they must try to reunite the Roman and Greek demigods, which Annabeth only knows the secret how to. The book is adventurous and funny. I recommend it to anyone who likes ancient Greece and Rome history.