I believe the answer is spelled out clearly in the Scriptures and by none other than our Lord Jesus Christ, the Authority of all authorities.
When the rich man of Luke 16:19-31 dies he goes to hades, a gehenna-like or hell-like abode for all unsaved. All such remain there until the Great White Throne Judgment Seat, the final place of judgment for those without Christ (Revelation 20:11-15). This takes place in a far off location after Christ's thousand year millennial rule on earth. The earth and universe, being cleansed, God now deals with the unsaved. Alone in outer space, Jesus meets sinners in a final day of reckoning.
The Apostle John tells us about this: "Then I saw a great white throne and Him who sat upon it, from whose presence earth and heaven fled away, and no place was found for them. And I saw the dead, the great and the small, standing before the throne, and books were opened; and another book was opened, which is the book of life; and the dead were judged from the things which were written in the books, according to their deeds. And the sea gave up the dead which were in it, and death and Hades gave up the dead which were in them; and they were judged, every one of them according to their deeds. Then death and Hades were thrown into the lake of fire. This is the second death, the lake of fire. And if anyone’s name was not found written in the book of life, he was thrown into the lake of fire" (Revelation 20:11-15).
At this place of judgment, "Death and Hades" are delivered up, judged, and finally "cast into the lake of fire." Notice, not some of Death and Hades, but apparently all.
So, back to Luke 16. The rich man dies and goes to hades, a place of where he was "in torments." He sought escape by calling out to Father Abraham. But Abraham could not release him and referred him back to his lifetime where he failed to get right with God. And then Abraham declared, "between us and you there is a great gulf fixed." He elucidates by saying that there is no passing from hell to Abraham's bosom (heaven) or vice versa. Is not this a clear and emphatic declaration?
The rich man begs for a miracle. If someone arose from the dead and went and preached to his brothers, perhaps they would be spared such a horrible fate. But the request is denied, Abraham saying, "'They have Moses and the Prophets; let them hear them.’ But he said, ‘No, father Abraham, but if someone goes to them from the dead, they will repent!’ But he said to him, ‘If they do not listen to Moses and the Prophets, they will not be persuaded even if someone rises from the dead’” (Luke 16:29-31).
In other words, the Scriptures are enough to save a soul. Faith alone saves a sinner. It doesn't have to be faith plus anything, not even a fresh miracle.
A final thought: all in hades will remain there until the Great White Throne Judgment Seat at which time they will be consigned to hell (gehenna) forever. Hell is described as a place of "everlasting destruction" (2 Thessalonians 1:9). I tremble!