In the wake of losing Corrie and Kevin, and not knowing how either of them are faring in enemy territory, the group's morale deteriorates and they spend the bulk of their time doing very little. Homer eventually takes the lead by calling for a group meeting and suggesting that they do something productive with their time and attempt to track down Corrie and Kevin. After spending some time scoping out the area, they release a smoke bomb into the hospital and investigate during the evacuation. They discover that Corrie is comatose and that Kevin was beaten when he arrived, but is otherwise healthy, but they are unable to do anything for either of their friends.
Fresh from the discovery of what had happened to their friends, the group agrees to make an attack on the convoys on the highway to Cobbler's Bay. The morning of the attack, however, Ellie tries to make conversation with Chris and realises that he is drunk. That afternoon, the group is surprised by an enemy sentry, but Homer pulls a sawn-off shotgun on them, despite their agreement that they would carry no weapons. The explosion of the convoy is successful, but Ellie is forced to kill a wounded soldier, an event which haunts her for the rest of the book. Not wanting to return to Wirrawee after this, they decide to investigate the other paths out of Hell to determine where they lead. Chris, however, decides not to go and to stay behind instead.
Their exploration leads them to a group of free Australians called "Harvey's Heroes", led by a man named Major Harvey, who exhibits extremely sexist and controlling behaviour. He refuses to allow any portion of the group to return to Hell to find Chris, and appears to have a particular vendetta against Ellie. It becomes clear quickly that Harvey is not actually a major, but in fact a school principal who, at one point, spent some time in the army reserves. Although Harvey brags about having made several enemy attacks, these attacks are revealed to be low-risk acts against abandoned vehicles and a "power station" they attacked turns out to be the local phone grid. The group is invited to spectate as Harvey's Heroes attack an abandoned tank, but they are led into an enemy ambush and have to flee from the scene, leaving most of their possessions behind; Fi is chased by an enemy soldier and Lee stabs him, reminding the others that their path back into Hell cannot be found out.
When they return to Hell, Chris is not there. They spend two weeks waiting for him, but there is no sign of him at all. More investigations into Wirrawee discover work parties of prisoners, including Corrie's mother, and early colonists. While camping in Robyn's music teacher's house, Ellie and Lee consummate their relationship for the first time, but Ellie feels betrayed when Lee reveals their love life by asking Homer for condoms. They move on to a church, where they keep watch over some of the early colonists, who have taken over several houses in the nice area of town, including Fi's house. Here they discover that Major Harvey, presumed dead in the ambush, is now working directly with the enemy. Reeling from this discovery, they arrange to blow up several of these houses using sparks from broken fuses to set off gas from ovens and heaters.
The experience is exciting and works well, but on their way back to Hell they see an overturned vehicle near a dam; further investigation reveals that Chris had overturned the car and died weeks ago. The book ends where it begins, with the group depressed and with low morale.