When I was acting, I got trained in creating a character as a three-dimensional person. If you're doing it right you should be able to draw an audience into the character's world and make them feel their fears.

But give me more credit than that. Someone else may have dealt the hand, but I picked it up off the table, I played every card, and I had my reasons.

I read a lot. I always have, but in those two years I gorged myself on books with a voluptuous, almost erotic gluttony. I would go to the local library and take out as many as I could, and then lock myself in the bedsit and read solidly for a week. I went for old books, the older the better - Tolstoy, Poe, Jacobean tragedies, a dusty translation of Laclos - so that when I finally resurfaced, blinking and dazzled, it took me days to stop thinking in their cool, polished, crystalline rhythms.

What I warn you to remember is that I am a detective. Our relationship with truth is fundamental but cracked, refracting confusingly like fragmented glass. It is the core of our careers, the endgame of every move we make, and we pursue it with strategies painstakingly constructed of lies and concealment and every variation on deception.

I can't explain the alchemy that transmuted one evening into the equivalent of years held lightly in common. The only way I can put it is that we recognized, too surely even for surprise, that we shared the same currency.

It took my breath away, that evening. If you've ever dreamed that you walked into your best-loved book or film or TV program, then maybe you've got some idea how it felt: things coming alive around you, strange and new and utterly familiar at the same time; the catch in your heartbeat as you move through the rooms that had such a vivid untouchable life in your mind, as your feet actually touch the carpet, as you breathe the air; the odd, secret glow of warmth as these people you've been watching for so long, from so far away, open their circle and sweep you into it.

Ireland is such a young society. The British were the ruling class up until they left about a hundred years ago, and we've been trying to work out what our class hierarchy is ever since.