What is the appeal of this story of the imagined invasion of Australia that so many readers continue to want more? Is it the allure of more of the same? Maybe, but each book, so far, has had its own mixture of heroics and inaction, winning and losing, happiness and sorrow; not all were constantly action-packed and continually fast-paced. Certainly, in this one there is plenty of heart thumping action, adrenaline pulsing tension, and shocking violence graphically described. There are the familiar lucky escapes, the post examination of the group’s forays, the taking stock, though there are fewer of the deep and meaningful conversations between the remaining young people, the five survivors whom readers have come to know and whose fates they desperately want to follow. And there is another reason for the attraction, the characters, Ellie, Fi, Homer, Kevin, and Lee – we’ve become attached to them.

Heroes they certainly have been but, in this book, there seems to be a querying of just how long one can remain a hero and what are the costs. Heroism is not hollow, but Ellie in particular seeks congratulations and acknowledgment from adults, like Colonel Finley, that what they have achieved is remarkable. The satisfaction in the deed itself is tempered too much by the sense of risk, how close they come to death, and how they must remind themselves that the people they are killing and maiming are soldiers, the enemy, not ordinary human beings like themselves. There is one telling episode where they use cunning to get themselves out of a situation that would normally require killing.

This shift in tone is also evident in the change in all the characters. Kevin has retreated from the bravado, the derring-do, and while Fi is sympathetic, Homer and Ellie are more ready to see him as a cot case. He moves towards some sort of recovery tending a neglected garden, but it is hard to picture him at the heart of guerrilla sorties in the future. Homer, the unpredictable larrikin, the light and the spark of the group, has sobered, and only cracks the occasional inappropriate joke. Fi reveals that she is haunted by images of death and human injury that the group have inflicted; that the soldiers are the enemy, that there is a ‘cause’, fails to diminish the pain. Lee has become hard, inaccessible, and driven, his values so skewed that he becomes involved in an almost unbelievable situation of potential danger to the group. Ellie, who has always contemplated the results of killing and its morality, is prompted to think on a larger, longer term scale about the effects of the war on not just the group but a future society.

And increasingly the spiritual cost rather than the material occupies her thinking. This is prompted especially by their encounter with a gang of very young, feral children, who jump them and steal their property. At last the five are being forced to look out beyond themselves and their own survival. In this book, the feral children do not form part of the main action though the reader senses there is more to come. Ellie, bossy, organising Ellie is surprised that her attempts to support them are ignored.

So there is volume five. Those who read the books for the edge-of-the-seat action will get their fair share. Those who respond to the emotional, contemplative, introspective aspects of the series will have plenty to respond to. Those who anticipate a resolution will be disappointed. We are told that two more are to come so there should be no false expectations. There is however, a definite shift of where this story of invasion is heading epitomised in the closing moments of the book; a shift big enough to make the reader tantalised about where the story might end and query whether there is an element of irony in the title.

You may think you have had enough after four books – after all it was originally a trilogy – but if you pick up this book to dip in you’ll find that you are galloping along with the narrative, unable to extricate yourself until those final words. And let’s face it. There’s a lot to be said for that kind of reading experience.