Idriess was a spotter for the famous Australian sniper, Billy Sing, and this book draws on his own experiences in the Gallipoli trenches during World War One. … Sing had a reputation as an excellent marksman, lurking in the dark and silently sneaking up on the enemy. One day he was shot by a Turkish soldier. The bullet travelled down the barrel of his telescope, wounding both hands then went through his mouth, out his cheek and into his shoulder. He recovered from the injury, but was never really the same. Book 2 of The Australian Guerrilla Series, produced by Idriess during World War Two for the Australian militia.