Piper went a little crazy. She cried out with relief and dove straight into the water. What was she thinking? She didn't take a rope or a life vest or anything. But at the moment, she was just so happy that she paddled over to Leo and kissed him on the cheek, which kind of surprised him. "Miss me?" Leo laughed. Piper was suddenly furious. "Where were you? How are you guys alive?" "Long story," he said. A picnic basket bobbed to the surface next to him. "Want a brownie?
Rick RiordanNow, as far as I knew, he (Luke) was still sailing around on his demon-infested cruise ship while the chopped-up Lord Kronos re-formed, bit by bit, in a golden sarcophagus, biding his time until he had enough power to challenge the Olympian gods. In demigod-speak, we call this a “problem.” - Percy, 'The Battle of the Labyrinth
Rick Riordan