Then Satan and those following him are hurled into the “lake of fire.” This is the “second death,” where, to all eternity, they are held in ‘torment’ (jailers were in olden times called “tormentors” [Matthew 18:34, Authorized Version]). They are ‘locked up’ in nonexistence forever.

Revelation 20:7-10 describes what occurs as a test on earth’s inhabitants:

And the Devil who was misleading them was hurled into the lake of fire and sulphur, where both the wild beast and the false prophet already were; and they will be tormented day and night forever and ever.”