Hertfordshire, October 5th 2016. At around 2 a.m., PC Dave Wardell and his dog, PD Finn, were trying to apprehend a robbery suspect when he turned around and attacked them. Finn was stabbed with a ten-inch-bladed knife, both through his chest, via his armpit and then - the knife bound for Dave - through the top of his head. Finn no doubt saved Dave's life, but the race was on to try and save Finn's. Dave Wardell's heartfelt memoir charts...