Dragged Together (A KotLC and PJO Crossover)

In New York: Humans are going missing. First it was just one, and then it was two, and suddenly they were disappearing every week and no one knows who is behind it.
In The Lost Cities: The Neverseen haven't struck in months and the Council and Black Swan are in the dark, with no idea what is going to happen next.
In Camp Half-Blood: Percy Jackson has gone missing, again, the Olympians have confirmed it was not them, and his mother said the last time she saw him, he was leaving the appartment to take a walk in the park.
In The Lost Cities: The Council and the Black Swan have heard about the disappearances, so they sent the Moonlark and her friends to investigate.
When the elves find the demigods, what will happen? Will they become allies? Or will they misunderstand and become enemies?
I do not own KOTLC or PJO, I do own some minor characters and the plot, but that is it. I do not own the cover.