Lucky Thing by Tom Baragwanath

When brilliant young student Jessica Mowbrie is left in a coma after being abandoned in a remote patch of New Zealand bush, the local Masterton police don't have a clue what happened. Isolated and under resourced, the detectives struggle to even begin piecing it together. Police records clerk Lorraine Henry will not accept that Jessie simply had a lucky escape. She thinks whoever hurt her needs to be hunted down, and worries that her employers are a bit hopeless. As Jessie's life hangs in the balance, it looks like Lorraine will do the hunting. She's not getting any younger, of course. But she has all the police records at her fingertips - and as much information about who hates who as anyone in their small town. Plus, she's used to being underestimated. And you should never underestimate a middle-aged woman with justice in her sights.