The Golden Amulet (PJO, Sequel to The Silver Ring)

Sequel to The Silver Ring.
Percy Jackson is finally having a normal life. Being married to Artemis but Zeus hating him, he counts himself lucky that he isn't embroiled in another war.
But his wishes get thrown out of the window when Chaos comes back into his life asking for help save a dear friend, which makes him realize that he can no longer pretend everything's fine.
However, not all is as it seems, and unfortunately, it looks like Percy's going to learn it the hard way, yet again.