The classic study of the BEKs is back in a revised 2nd edition, with an additional chapter from Brian Bethel reflecting on his encounter
From the cover:
Strange children are appearing around the world. Attired in old fashioned clothing, their skin is pale and their mannerisms awkward. Their most startling trait, however, is their solid black eyes. They are knocking on doors and rapping on windows. Their voices are monotone and demanding and they have one simple request:
They want to come in. Cover art by Sam Shearon