Piper thinks that everything is happening like her dream said it would. We don't know what the dream is yet, but presumably the book will get around to telling us soon.
Piper is also still bummed because her boyfriend doesn't remember her. We feel you, girl.
Annabeth explains that they're all going to Camp Half-Blood, and Butch explains that they're all demigods.
We also learn that Annabeth is the daughter of Athena, and Butch is the son of Iris.
But enough talk—back to action: More wind-spirits appear to chase their flying chariot pulled by pegasi. The chariot makes a crash-landing in the lake by Camp Half-Blood, and creatures in the water grab them and throw them to shore.
On shore they meet the people from Camp Half-Blood. The Half-Blood people wonder why Piper and Jason and Leo haven't been claimed.
A girl named Drew stands up and says some snotty things. Thanks, Drew.
A fiery hammer appears over Leo's head. If this were a movie, there would be dramatic music, but since it isn't, everybody seems to take the appearance of the hammer fairly calmly.
Annabeth explains that this is a claiming—a god recognizes his or her children. The hammer means Leo is claimed by Hephaestus, god of fire and forges and building stuff. Sort of a high temperature lego god.
Leo is taken off to Cabin Nine, home of the children of Hephaestus.
Under Annabeth's prompting, Jason discovers a tattoo on his arm with a Latin inscription, though he doesn't know what it means or where he got it. Perhaps he is the child of Tatooine, God of Tattoos and muppet aliens (probably not, though).
Annabeth sends Jason off to see Chiron, the camp adviser, and decides to give Piper a tour of the camp.