We need to talk

When Zeus was alone a bird would find him telling him that a friend wished to talk with him about a mutual concern they had about the Asgardians.  If he wished to talk he should meet him on the isle of the Glass Tower in Avalon and the arrangements to keep the meeting secret will have been set in place on that side. When the bird finished talking it would disappear in a shimmering of lights as though it was never there.