Watch out, sunseekers, because a big, moving shadow is now swooping across you. Look up! Is it a bird? A plane?

Whatever it is, it's shining iridescently blue in the light, with huge wings catching the thermal confusions at the edge of the beach and the waves. The moving but unflapping wings and trailing tail give a look almost like a marine animal--but, no, look closer, and you can see the hints of a humanoid outline in the middle of the soaring material, and what might be a segmented, glossy-faced helmet...