What happens to Satan when the thousand years of Revelation 20 are expired?

Les teaches that when the thousand years are expired, Satan shall be loosed out of his prison. During the kingdom he had been held and incapable of causing mayhem, but he is then set free and goes right back to his old domain, planet earth, where Christ has been ruling for a thousand years. He goes out to deceive the nations. Les also says that after the judgment of Matthew 25, the survivors of the kingdom age—Gentiles—will probably go back to their original homeland and become the progenitors of the nations once again in full bloom at the end of the thousand years. Satan then goes out once more to thwart God’s plans, deceives the nations, Gog and Magog, and gathers them to battle—another battle of Armageddon, so to speak—with numbers as the sand of the sea. They come from every nation on earth and pass the camp of the saints about the beloved city, Jerusalem. But this time God does not delay; grace will not be operating, but judgment. In one short swift stroke, fire comes down from God out of heaven and devours them. The transcript then points to verse 10, but the supplied context ends before supplying its text.