I don't own Garrett, the concept ofThief, or anything you recognise in this story.

I'm sitting on the wall top of a mansion on the outskirts of the City. You know the sort of place. It's just far enough away from the stink of the Docks, but close enough to avoid the common farms in the proper countryside. The sun has just gone down, so I've got all night for this little jaunt.

There's a guard right below me. From his pose I'd guess he's asleep. He's leaning on the wall, hasn't moved for thirty minutes. There's a jug by his feet. Why do they make it so easy?

I leap down, land silently, and cross the courtyard. There's a grand entranceway ahead but I ignore it. That's the way they expect you to go in these days. I'd bet my last coin the hall beyond is full of guards.

I hug the shadows along the house wall. Somewhere around here there must be another way in. I keep close to the shadows and explore.

Let me tell you why I'm here. Perry got word of a merchant who'd brought back some strange artefacts from his last voyage. The Keepers were sniffing all over them, thinking they might be worth something. They finally let him get into the City with his stuff, and he came straight here.

Perry also said if I could get my hands on one particular item among the stash he could get me a good price for it. The rent is due again, and I'm halfway down my last purse. At least I won't jingle and give myself away. Normally I wouldn't touch anything the Keepers are interested in, but I'm desperate.

I'm looking for something called 'The Star Stone'. Trust the Keepers to want something with such a grand and yet unimaginative name as that. Perry's source says I'll recognise it as soon as I see it. But let's be honest. As long as I get a good price for it I don't care what it's called.

I find an open window. It's on the first floor, but there's a tree growing near and it's the work of a moment to climb in and snuff out the two candles on the table. It takes my eye a moment to adapt to the darkness beyond the shaft of moonlight but my mechanical eye helps me. In a few seconds it's clear as day in here to me.

I'm in some kind of study. The table has three books open on it, and a pile of papers where somebody has been making notes. I leaf through. It can't hurt to look, can it? But the papers are covered in Keeper Glyphs, strange ones I'm not familiar with. It makes my nose itch to look at them, so I drop the papers again. I help myself to the pen – it's rosewood inlaid with gold designs. Very nice, very expensive. The books are in a language I can't read so I ignore them too.

The door out of the room is open just a crack. I put my mechanical eye to it. Beyond is a library. It's well lit and I can hear voices, close to me. I trust to my equipment – I paid enough for it – and roll a spying orb into the room beyond.

The double vision is nauseating but I fight the urge to vomit.

Through the orb I see a network of bookshelves, all well lit, but no people anywhere. I leave the relative safety of this dark room and step out. The voices are coming from somewhere ahead.

I pick up my orb. The lens is cracked. Serves me right for going for the cheaper option.

Pressing myself up against the shelves I edge closer to the voices. Before me the shelves give way to a large square area with a table in the centre. Four Keepers are poring over some large papers. I can't quite make them out, but they look like maps.

Artemus is there with three others that I don't recognise. One is a slim woman and the other two are slightly overweight and balding men who could be twins. They aren't talking, and I can smell the tension between them.

A man enters directly across from me. Carefully I ease myself as far out of sight as I can. Not too quickly though, as the eye is drawn to sharp movements. This man is dressed gaudily. He has a finely waxed moustache and his black hair is drawn back in a tight ponytail. He has the look of a merchant, and the rolling gait of a sailor recently back from sea. I suspect this is the man I've come to relieve of his possessions.

'Keeper Artemus, greetings.' His voice is as oily as his hair. 'Have you looked over my wares?'

'I have.' Artemus speaks in that cold voice he reserves for non-Keepers.

'Did anything catch your eye?'

'Tell me, did you put ashore on Carenole?' Artemus is glaring at the merchant pointedly.

'Well, it's forbidden.' The merchant starts to sweat.

'I know it is,' snaps Artemus. 'Did you?'

'My ship needed water and supplies. We had to stop.'

'You took these things from the Keeper Temple there.'

Carenole? I never heard of the place when I lived with the Keepers. I thought I knew all the Keeper Temples, just so I could avoid them.

'Good Keeper, I assure you I did not.'

'Then someone on your crew did. Do not presume to bandy words with me, man, I know when you are lying.' I haven't seen Artemus this angry for a long time.

'Will you offer me a fair price for them?'

Artemus turns almost purple with rage. 'A fair price? By rights these artefacts belong to Keepers. You are lucky I do not charge you with trespass. I always knew you were a common thief and a highway robber, but I never thought to see you sink so low as to steal from Keepers.'

There's fear in the man's eyes now, and he takes a step back. 'Of course, good Keeper. Naturally you must take what you will. If you need any assistance unpacking the crates in the attic I will be most happy to help.' The coward backs from the room, almost running. I didn't think Artemus had it in him to be so intimidating. Whatever the merchant took, and whatever Carenole is, they must be very important to the Keepers.

I want to take a look at these crates in the attic before Artemus does. I don't want to chance them finding the Star Stone before I do. It can't be as important to them as it is to me.

I leave the library, creeping back towards a dark corridor. I follow it through until I reach a great open hall. There's a stairway ahead, a great grand affair. It's not well lit, and I decide to chance it. Time is of the essence.

I take the filigreed gold candlesticks from every alcove on the way up. No sense leaving them to gather dust here.

The stairway opens into a hall. It's the smart area of the house. I curse under my breath. I'm not going to find the way to the attic here. There's a servants' door at the end of the hall, concealed so the rich don't have to see the people who wait on them. I spot it right away and let myself in.

It's dark within. I feel a bit more confident with every minute I spend in this house. The servants' area would be lit all night long if anybody was in the house except my friends downstairs. I saunter upwards casually. There's never anything to steal in these narrow servant corridors.

After a few flights the stairs end in a doorway ahead. I open it and look through. There are lots of crates here, covered in white sheets. I step through the door. This is almost too easy.

Three steps into the room and I feel someone in my head with me. She's just watching right now. How did she get in so easily? How long has she been there? Normally when the Keepers try to spy on me I can avoid them, but this person has just waltzed right in.

I don't mind admitting I'm unsettled. I've stopped just inside the room, unsure of what to do next. Should I wait and see if this visitor leaves? I want to throw her out but I can't seem to focus on where she is. If you don't know, having someone in your head feels like a hand on your shoulder. You can grip it and throw it off if you concentrate the right way. But whoever this is, she's an expert. Her touch is a breeze on the back of my neck and I can't push her away.

Should I wait for her to go? Or should I carry on hunting for the Star Stone?

As I think this, she moves. I feel her jump as if startled, rearing like a startled horse. The Star Stone? It's her thought, echoing mine. No!

There's white hot pain in my head. Something hits me in the face. Through my mechanical eye I see floorboard. It comes to me that I've fallen just before I pass into nothing.