Bettrys knows that Percy is here to do something big now, but she didn't get any details on what, nor does she know she's too late to stop it, technically, yet. She's going to be doing her best to track him down next week and she'll deal with the Ocean when she figures out that's who she's talking to now.

She'll also probably start looking up exorcism rituals after that encounter, because having a major genius on the level of Albion (if not stronger) kicking around Albion uncontrolled is almost as bad an idea as having two eligible heirs to the throne is.