I made my usual cautious way through the caverns, deep in thought, with just a couple of changes on the transit tubes which link underground spaces all over the world. They are not actually tubes or tunnels, of course; this is just the best rendering of the word into human languages. In reality, they are a magical form of transport, instantly moving goods and people from one cavern to another, travelling hundreds or even thousands of miles in an instant. The entrances and exits are numerous and often crowded with travellers from all parts of the Lower Realms; Goblins of every description hurrying home or on errands of their own. The tubes also served a secondary purpose from my point of view: they were the perfect way of losing anybody who might be trying to follow me.

As I have mentioned before, I advertise my office address and telephone number in a few select places, and quite a number of much more obscure ones. You'd be surprised how many clients I pick up from a card left behind in a bar, or from the Classified Ads section of glossy magazines targeted at the female of the species. I'm much more careful about my apartment, my home. I keep it out of the public eye, out of the public record - as far as is possible - and I have identified a whole host of hidden routes that obscure my destination whenever I go back there.

So I should not have been at all surprised to discover Trinity in my apartment when I got home. It seemed it was my month for siblings.

"Hi, sis," I said, feigning a casualness I did not feel while I hung my coat and hat on the stand by the door.

Trinity Gask is my kid sister, as much younger than me as I am younger than Nether. All grown up now, of course. She always was a wild child, determined not to conform to the conventions of society or the expectations of parents and teachers. This may be a family trait. While still in her third decade, she ran away from home several times, to be returned the first time under the escort of two stern-faced members of the child protection agency. The other times she came back just because she wanted to: no explanations, no reasons given. She just expected to be welcomed with open arms, which our parents did unhesitatingly.

The last time Trinity had deigned to come home was when Mother was still lingering on her deathbed. Father had died some years before - suddenly and unexpectedly - and Mother never really recovered from the shock. Trinity arrived on the doorstep in the company of a male, one Forneth Butterstone, a fussy-looking and over-dressed individual, and one who was suspiciously vague in describing what he actually did for a living.

I confess I didn't like Butterstone from that very first meeting, an opinion amplified when Trinity declared she was going to marry him. She was evidently completely besotted, repeatedly swearing eternal fidelity and life-long togetherness. To me, though, it was transparently obvious that he was only interested in my parents' money. Not that there was a huge amount - my parents were never really rich - but they had been just wealthy enough to attract the attention of a swindler and confidence trickster.

I set myself a task which determined, to a certain extent, the future direction of my life. I set out to prove that Trinity's intended was not all she could see on the surface. It turned out to be easier than I anticipated. Butterstone made no attempt to conceal his womanising and profligate behaviour, and it was but a few hours work to tail him and take a few photographs, which I duly presented to Trinity at the earliest opportunity.

Her reaction to Butterstone's perfidy was at first predictably dramatic: hysterical crying interspersed with rants and curses and imprecations, all uttered at full volume while pacing the tiny apartment she rented. It was unfortunate that her soon-to-be-ex fiancé turned up a few minutes later, although quite definitely fortunate for him that I was still there. Trinity's reaction as Butterstone strolled in was one of the most frightening things I have seen in a long career. Her face hardened to a mask of fury and she grabbed the two largest knives from the kitchenette and advanced on her erstwhile fiancé.

Butterstone froze in the doorway, eyes wide in terror and seemingly unable to move a muscle. I swear to this day that Trinity would have carved off his ears, at the very least, if I had not stepped in and wrested the knives from her hands. I pushed the now-disarmed Trinity onto the davenport with more force than was, perhaps, strictly necessary and shouted at Butterstone to get out. He emerged from his catatonic state, shrieked wildly and fled, slamming the door behind him. I never saw him again.

Part 18

Part 20