It’s a confronting title – and a confronting book, too. But Jeff Sparrow’s literal and metaphorical journey into the dark heart of this subject is also completely and utterly fascinating.

Sparrow is mildly intrigued, then distractedly obsessed, with the grisly discovery of a severed, boxed head of a Turkish soldier, kept as a trophy by a Gallipoli veteran and handed in to Echuca police. What makes a person salvage and treasure something like that? What does that say about their attitude to killing? And how does the experience of killing transform someone? Sparrow’s inquiry into the origins of the head soon becomes something else entirely, as he hangs out with a Queensland roo shooter; tours a Melbourne abattoir; interviews a prison warden and an executioner; talks to America’s leading expert on methods of execution; and meets with various Iraq veterans.

This is a fantastic work of reportage, both accessible and deeply, intelligently thoughtful. Like Jon Ronson in the more playful Men Who Stare at Goats, or Maria Tumarkin in Traumascapes and Courage, Jeff Sparrow makes the reader a front-seat passenger on the ride, inviting us to follow his logical trail of breadcrumbs and make our own conclusions alongside him.

‘If you didn’t want to look, didn’t that suggest that there was a reason to open your eyes?’ Jeff wonders at the beginning of his journey. Indeed.