The di Angelos would leave the Lotus Hotel in late October of the coming year. He had established this in his timeline work — the Titan's Curse events placed Westover Hall in December, which meant Nico and Bianca had approximately six weeks in the real world before the school attack.
He could not reach them in those six weeks. They were in Maine, placed there by Hades's people, isolated and guarded in the way that powerful demigods of particularly sensitive divine parentage were guarded. He had no legitimate access, no cover story, no path through the Mist to them in that window.
Westover Hall itself was the only viable option. He had known this for years; what he had been working out was how.
The solution arrived in April, with the help of someone he had not expected.
Annabeth came to him in the library with a scroll and an expression that meant she had been thinking about something for a while and had reached a conclusion. She sat down and said, without preamble: 'You need to be at Westover Hall in December.'
He looked at her. 'Yes.'
'For the di Angelos.'
A pause. 'You've been working on this.'
'You told me last September that the Titan's Curse involves a school attack and the di Angelo siblings,' she said. 'I have been thinking about the logistics of how you get there in a way that makes sense. Grover is the assigned satyr for the Westover Hall territory — I know this because Chiron has his satyr assignments in a file and I may have looked at it.' She met his eyes, unapologetic. 'Grover will be there ahead of the camp-based group. Annabeth and Percy and Thalia go as the rescue group. That is the known assignment.'
'Yes,' he said.
'There is also a role,' she said, 'for someone who arrives at Westover Hall just ahead of the primary group. Not on the official quest — the quest has its three people. But as independent reconnaissance, with Chiron's blessing. I think that role is you.'
He sat back. He had not thought of it this way — as a separate, Chiron-sanctioned reconnaissance rather than an improvised presence. The difference was significant. An official reconnaissance gave him a legitimate reason to be there, a cover story that would hold, a reason to have arrived at the school before the battle rather than appearing from nowhere in its middle.
'Chiron would need to agree,' he said.
'I think he will,' Annabeth said. 'You've been at camp three years. Your intelligence work is good — he knows this. And he knows you have some foreknowledge about events. He will put it together if you give him the opportunity.'
'You're saying I should tell Chiron enough to make the case.'
'Enough. Not all of it.' She looked at him steadily. 'I trust you to know what enough is.'
He thought about this for a long moment. He thought about Chiron — the centaur's ancient perceptiveness, the trust they had built across three years. He thought about what partial truth looked like when offered to someone with three thousand years of experience reading partial truths.
'Yes,' he said. 'Okay. I'll talk to Chiron.'
Annabeth picked up her scroll. 'Also,' she said, 'the di Angelo girl's name is Bianca. I know that's not what you said in the briefing. But you said 'Bianca' once, in October, when you were talking about the Junkyard of the Gods sequence. I've been waiting for you to explain that.'
He looked at her. She looked back.
'I'll tell you everything when we're at Westover,' he said. 'After. When the outcome is known.'
'All right,' she said. 'After.'