"They Came On Doomsday" is about Judgment Day, when the war between Good and Evil breaks out. When the World Central Government of the elite ruled the Earth, a legion of beastly creatures come to Earth from a distant dark planet to assist Lucifer in the extermination of humanity. However, human beings have their guardian angels; they are interstellar warriors...

"...It was exactly one O'clock in the afternoon on May 20, 2030, when he first noticed it; that dark spot in his house backyard. It was a strange, black circular blot where there had to be sunlight. At the beginning, he thought it might be a tiny passing cloud, casting its shadow down to earth. However, not only was it perfectly round, but it was much darker than ordinary shadow...
...It seemed to be projected down onto the lawn by some mysterious object hovering high above in heavens...Sophie sat on the low stool and stooped over the telescope eyepiece to take a look at that mysterious object...'More than a flat disk, it looks like a pitch-black gaping hole to me, like the entrance to a tunnel, but instead of being a mountain tunnel, it's a tunnel that opens up deep into outer space. What if it doesn't move at all; I mean, what if it doesn't rotate in unison with the Earth. I'm not quite sure, but I think that tunnel opens up at exactly the same time every day as it aims at a particular place on the surface of our planet, pointing or maybe aligning itself with a distant galaxy,' Sophie said..."