Prologue:

It was midnight when the Lord of the Sea got an urgent message from one of the Naiads in New York. Poseidon sighed, "What is it now?" Naiads were always coming up with complaints to him about something or other.

"No idea my lord." The messenger said. "But she sounded worried about something. She said that it was a matter of most importance and that you should meet her personally for she wouldn't tell anyone else."

Poseidon paused. That was strange behavior for a Naiad, but he supposed visiting New York wouldn't be so bad. Maybe he could check on a certain child of his… and his mother.

"Fine" He said and the messenger left.

Turns out the Naiad lived in one of the streams in Camp Half-Blood. He found the Naiad sitting next to the rocks the kids call Zeus' fist.

The Naiad bowed nervously. "My Lord" she said "Thank you for coming. I just found out some rather distressful news."

"What do you mean?" Poseidon asked curiously.

The Naiad shifted uncomfortably. "Well, my lord, I came here about an hour ago following Luke-"

"Hermes' Child?"

"Yes, thought he looked different, almost" she paused "evil. And as soon as he got here he began to chant something, but not in Greek. The language sounded ancient, old and powerful and it got really dark and cold. Then I could hear another voice colder and eviler. It spoke of a plan to sabotage the Olympians and it asked him if he was ready to do his part. He said yes and that he would get them by Winter Solstice, the day the campers get to go to Olympus."

"Get what?"

"Zeus' bolt and Hades' Helm."

He stood staring at her shocked. No it couldn't be, but there is no one else who would do such a thing. He didn't even dare to say his name.

Poseidon sighed. Looks like he was going to see his son after all.

This wouldn't be a happy family reunion.

Not at all.