Events in the Maunsworth Array have led to a resonance in the Standing-Point Field that has hurled Grace and Thomas back into the Heavenfield, but worse, has allowed a terrible creature out into the Array Hall.
Stuart Nicks, together with three soldiers, finds himself chasing after the creature in a desperate attempt to prevent it escaping into the Array tunnels, and from there out into the world.
Meanwhile, Thomas and Grace have found themselves on the edge of another Heavenfield reality, alone with the Angel, and the approaching armies.
The three forces, British, American and Exile, unable to retreat, must defend the open Entry-Point. They cannot allow any more creatures through, and can only dig in and await the inevitable onslaught....
Grace and Thomas are surrounded, alone with the Angel, confronted by the Demon Girl.
The three forces of the British, Americans and Exiles prepare their defences, as outlying troops at Palmer's Point meet the first onslaught. But they are quickly overrun, and fall back to high ground.
Meanwhile, the army of monsters march on inexorably towards the Maunsworth Entry-Point, a seemingly unstoppable storm...
The three forces of Americans, British and Exiles, under the guidance of the Angel, are forced into an uneasy alliance against the threat of the approaching Demon army. The creatures, led by the female entity, are intent upon breaking through the Maunsworth Entry-Point and out into the everyday world.
Thomas and Grace travel back from the Heavenfield to the Array Chamber, but during the transition Thomas is surrounded by a host of Angelic creatures, who decide to lend their support against the Demons.
Meanwhile, Alex has a visitation from the Demon Girl, who forces him into a confrontation that leads to a terrible chain of events, which sees Thomas and Grace hurled once more back into the Heavenfield...
Alex has taken Grace and Thomas hostage, forcing them to travel back into the Heavenfield, just as both the American and Exile forces are drawn up to do battle.
He leads them to the ruins beyond the valley in a desperate search for the Angel, but Thomas escapes with Sanders, and Alex is recaptured.
As they flee, Gutteridge apprehends them, chasing Thomas down into the Angel's tunnels. Thomas finds the Angel, who intervenes just as the Americans and Exiles launch their attacks.
It seems as if disaster has been averted, but Alex has chilling news. The horde of Creatures, led by the Demon Girl, may have followed them to Maunsworth, intent on destroying them all....
Speers and his forces have broken the cordon around the American Entry-Point, and have made their way to the British E.P. just in time to confront the Exile forces, newly-arrived from the destruction of their Fortress by the Demon army.
The Demon Girl, manipulating all sides, tells Speers to send Gutteridge to the ruins around Maunsworth, for a chance to kill Thomas Sullivan, who she perceives as a threat to her plans.
Meanwhile, Alex has taken Grace and Thomas hostage in a desperate attempt to re-enter the Heavenfield and end the prophecy of the 'Final War'....
The British forces at Maunsworth are concentrating upon building their fighting strength, in response, not only to the Exile cordon around their Entry-Point in the Field, but also towards the increasing political tensions with the Americans (whose policies are fuelled by Speers' paranoias).
Grace and Commander James face painful times as they interrogate their prisoner Alex, who reveals some disturbing facts about his past, and also warns of a terrible danger approaching Maunsworth.
Meanwhile, since returning from the Field, and his encounters with the Angel, Thomas Sullivan is finding himself increasingly assailed by visions and dreams which, while lending him a unique insight into the true nature of the Heavenfield, threaten to overwhelm him....
Now that the Americans have their own Array up and running, they have entered into a desperate arms-race to break the siege around their Entry-Point into the Heavenfield. Speers, in charge of the American forces, is still unaware of the attackers' identity, and is mistakenly convinced that it is the British that hold the Field.
Meanwhile, Alex, having escaped the Exile fortress, has reached the Maunsworth Entry-Point, and finds himself a prisoner once again, this time to the British. Henschel, having helped Alex escape the fortress has opened it up to the attacking Demon army, sealing its destruction.
The British expedition team fight their way back to the Entry-Point and escape to safety, but the Exile forces hold the Heavenfield-side of the Doorway now.
The spy within Maunsworth, who has been passing information to Gutteridge and the Americans has been uncovered, and her attempts to destroy the Array averted. For the time-being it seems that all forces face an uneasy stalemate...