The Final Battle will soon be upon them...

Back in Chicago, a broken and battered Artemus and Smokey sink into despair, the loss of the man they were born to protect a burden they cannot bear, much to the frustration of the Guardians and super soldiers who remain at their side.

When a group of unexpected visitors turn up at the mansion, Artemus is forced to face the ramifications of their failure in Rome and finally finds his resolve to enact the desperate plan he's put together to save his brother. But after the world's most powerful governments decide Artemus and Smokey are too valuable an asset to risk losing to Hell, their former associates turn against them and try to capture the angel and the hellhound as a safeguard.

Trapped in the Underworld, Drake Hunter must survive in a realm that no living human has ever set foot in before. Much to his surprise, he is rescued from the clutches of Ba'al's leader by a demon who was once his enemy and soon finds himself in the company of the most unlikely group of allies he's ever worked with.

As Artemus and Drake gather their troops on Earth and in Hell, Satanael and Hell's Council finally make their move to capture the two brothers and bring about the Apocalypse they have long wished for.

With the fate of the world hanging in the balance, can Artemus and Drake defy the destiny Hell wishes to impose upon them? Or will they achieve the impossible and win the fight of their lives?