'Shaft Of The Abyss' in the Bible

And, the fifth messenger, sounded; and I saw a star, out of heaven, fallen unto the earth, and there was given unto him the key of the shaft of the abyss.

And he opened the shaft of the abyss; and there came up a smoke out of the shaft, as the smoke of a great furnace, and the sun and the air were darkened, by reason of the smoke of the shaft.