He was a legend: Frank Mackey, still in his thirties and already running undercover operations; the best Undercover agent Ireland's ever had, people said, reckless and fearless, a tightrope artist with no net, ever. He walked into IRA cells and criminal gangs like he was walking into his local pub. Everyone had told me the story: when the Snake--a career gangster and five-star wacko, who once left one of his own men quadriplegic for not buying his round--got suspicious and threatened to use a nail gun on Frank's hands, Frank looked him in the eye without breaking a sweat and bluffed him down till the Snake slapped him on the back and gave him a fake Rolex by way of apology. Frank still wears it.

I was a shiny green rookie, only a year out of Templemore Training College. A couple of days earlier, when Frank had sent out the call for cops who had a college education and could pass for early twenties, I had been wearing a neon yellow vest that was too big for me and patrolling a small town in Sligo where most of the locals looked disturbingly alike. I should have been nervous of him, but I wasn't, not at all. I wanted the assignment too badly to have room for anything else.

His office door was open and he was sitting on the edge of his desk, wearing jeans and a faded blue T-shirt, flipping through my file. The office was small and had a disheveled look, like he used it mainly for storage. The desk was empty, not even a family photo; on the shelves, paperwork was mixed in with blues CDs, tabloids, a poker set and a woman's pink cardigan with the tags still on. I decided I liked this guy.

"Cassandra Maddox," he said, glancing up.

"Yes, sir," I said. He was average height, stocky but fit, with good shoulders and close-cut brown hair. I'd been expecting someone so nondescript he was practically invisible, maybe the Cancer Man from The X Files, but this guy had rough, blunt features and wide blue eyes, and the kind of presence that leaves heat streaks on the air where he's been. He wasn't my type, but I was pretty sure he got a lot of female attention.

"Frank. 'Sir' is for desk jockeys." His accent was old inner-city Dublin, subtle but deliberate, like a challenge. He slid off the desk and held out his hand.

"Cassie," I said, shaking it.

He pointed at a chair and went back to his perch on the desk. "Says here," he said, tapping my file, "you're good under pressure."

It took me a second to figure out what he was talking about. Back when I was a trainee posted to a scuzzy part of Cork city, I had talked down a panicked teenage schizophrenic who was threatening to cut his own throat with his grandfather's straight razor. I had almost forgotten about that. It hadn't occurred to me, till then, that this was probably why I was up for this job.