The Argo II is a flying Greek trireme (that could also sail if the aerial controls are damaged) built by the Hephaestus' Cabin for the journey of the seven demigods of the Prophecy of Seven to Greece. It was manned by Leo Valdez, Piper McLean, Jason Grace, Frank Zhang, Hazel Levesque, Percy Jackson, and Annabeth Chase. After facing Scylla, Percy got mad, like really mad at you because you sacrificed six fellow demigods that were traveling to make your way through the monster.