"the mystery of the woman and of the beast"
Revelation 17:6-14 When I saw her, I was greatly astonished. Then the angel said to me: "Why are you astonished? I will explain to you the mystery of the woman and of the beast she rides, which has the seven heads and ten horns. The beast, which you saw, once was, now is not, and will come up out of the Abyss and go to his destruction. The inhabitants of the earth whose names have not been written in the book of life from the creation of the world will be astonished when they see the beast, because he once was, now is not, and yet will come.
"This calls for a mind with wisdom. The seven heads are seven hills on which the woman sits. They are also seven kings. Five have fallen, one is, the other has not yet come; but when he does come, he must remain for a little while. The beast who once was, and now is not, is an eighth king. He belongs to the seven and is going to his destruction.
"The ten horns you saw are ten kings who have not yet received a kingdom, but who for one hour will receive authority as kings along with the beast. They have one purpose and will give their power and authority to the beast. They will make war against the Lamb, but the Lamb will overcome them because he is Lord of lords and King of kings—and with him will be his called, chosen and faithful followers."