User blog comment:Hyperborean/"The House of Hades" – official expectations blog/@comment-122.167.5.165-20130420134022/@comment-3146930-20130420183624

Poseidon is pretty much the only god we haven't heard from at all. I mean if you look at all the other members of the seven, all of them have had some kind of contact with their Olympian parent except Percy. I mean we don't really see Zeus/Jupiter either, but Zeus is talked about a lot and he did help Jason beat that one Gigantes. Aphrodite and Hephaestus appeared to Piper and Leo in their dreams. Pluto was in a flashback and he can't really appear to Hazel or he will be forced to return her to the Underworld. Mars appeared in person before the Romans and appeared when Frank got to his house in Canada. Athena/Minerva appeared to Annabeth in a subway station in a flashback.

So far Poseidon has only been mentioned once, making me wonder if something is going on with him...