Then Death and Hades were thrown into the lake of fire. This is the second death--the lake of fire.

1 Corinthians 15:26
The last enemy to be destroyed is death.

Revelation 1:18
the Living One. I was dead, and behold, now I am alive forever and ever! And I hold the keys of Death and of Hades.

Revelation 2:11
He who has an ear, let him hear what the Spirit says to the churches. The one who overcomes will not be harmed by the second death.

Revelation 6:8
Then I looked and saw a pale green horse. Its rider's name was Death, and Hades followed close behind. And they were given authority over a fourth of the earth, to kill by sword, by famine, by plague, and by the beasts of the earth.

Revelation 14:10
he too will drink the wine of God's anger, poured undiluted into the cup of His wrath. And he will be tormented in fire and sulfur in the presence of the holy angels and of the Lamb.

Revelation 19:20
But the beast was captured along with the false prophet, who on its behalf had performed signs deceiving those who had the mark of the beast and worshiped its image. Both the beast and the false prophet were thrown alive into the fiery lake of burning sulfur.

Revelation 20:6
Blessed and holy are those who share in the first resurrection! The second death has no power over them, but they will be priests of God and of Christ, and will reign with Him for a thousand years.

Revelation 20:10
And the devil who had deceived them was thrown into the lake of fire and sulfur, into which the beast and the false prophet had already been thrown. There they will be tormented day and night forever and ever.

Revelation 20:15
And if anyone was found whose name was not written in the Book of Life, he was thrown into the lake of fire.

Revelation 21:4
He will wipe away every tear from their eyes,' and there will be no more death or mourning or crying or pain, for the former things have passed away."

And death and hell were cast into the lake of fire. This is the second death.