In an upcoming General Hospital episode, we learn more about Lucy's vampire craziness during her psychic break.
Kevin Collins (Jon Lindstrom) tells the story to a harassed John McBain, who is concerned that Lucy believes him to be this vampire named Caleb.
Kevin has a daughter, Livvie, he tells McBain, and she married a man named Caleb and disappeared. Lucy still feels very guilty and upset about that situation.
With the financial stress Lucy has due to Coe-Coe Cosmetics, plus her return to Port Charles and all the emotions it stirred up, Lucy had a breakdown and imagined these vampires.
This doesn't gel, I don't believe, with the vampire story on Port Charles. Here, it's all in Lucy's head.
By the way, Collins' daughter Livvie was played by Kelly Monaco on Port Charles.
So GH gets to bring in the fact that all of these actors were fellow vampires, use it to get Kevin Collins to town, and then have it all explained away.