Percy and Nico entered the garden of the house where their sparrow, Luke Castellan, once lived to understand his story, according to Nico, to help them fight the Titans. Percy didn't quite get what was going on, but he didn't want to be here even more when he saw:*

The path to the house was decorated with a path made of stuffed animals, on the bright turquoise door it was written in several languages: Castellan, above the door hung a lot of bells that made noise at every slightest gust of wind

It was the middle of the night, so Percy and Nico were surprised when Luke's mother opened the door, and immediately shouted at the sight of them, "Luke! I knew you'd come back"- it took some time before she seemed to understand that we weren't Luke (we weren't like Luke at all), but she invited us out for cookies anyway. We sat at a table where there was a lot of marmalade sandwiches and cookies... some looked like they had been lying here for a few years*

Before they started talking, Y/n, the daughter of the goddess Iris and Luke's girlfriend, came out of the room. They had no idea what she was doing here, but Percy recognized her, she had been in the camp when he first came there, except she was 16 and Luke was 18. Now Y/n was a grown woman. It was probably not a coincidence that Luke's girlfriend is at his mother's house. Nico didn't recognize Y/n, because he joined the camp when Y/n had already disappeared with Luke and a few others who had defected to Kronos' side - Percy, to put it mildly, didn't like Y/n because of Luke, but before he found out that you were part of Krtonus's army, he thought you were nice and friendly