It seemed as though we'd been back at school forever when in reality it was barely the end of May. My mother had returned from her honeymoon, rested, tanned and happy, her bump seeming bigger than ever. Lily and James were still going strong and driving everybody crazy with their soppy moods and soulful glances. Sirius and I were still quite happily bumbling along with the occasional dustup but most surprisingly of all were Jazz and John Caldish who were not only still together, but blissfully happy with it.

The sun, perhaps sensing that it was time for summer to begin, had broken through the layer of grey clouds that had been sculling around the castle for a few days now. It was making the lake dance and I wanted more than almost anything to be out there swimming in the sunshine. Still, more evenings than not, I found myself in a dark corner of the library poring over textbooks or testing myself on poison antidotes or reciting the twelve uses of dragon's blood under my breathe, fingers stuffed into my ears.

By nature I was lazy. Throughout my O.W.L.s I had procrastinated, putting off my revision again and again until I finally just flicked through some of my notes the week before my exams. I was clever enough to pull decent grades without trying so I didn't bother - getting mainly 'A's, a couple of 'E's and, incredibly, an Outstanding in Astronomy which had always been my favourite lesson and one of the only classes I actually worked hard for.

This time round, however, I was working. Revising harder than anything else I had ever done in my life. I couldn't say I was enjoying it because I wasn't, most of the time I hated it, wanting to be drawing or swimming or spending time with Sirius. But in less than three weeks time exams would be over and I would be free. Free for summer to begin. It was all about the bigger picture. I get the grades now - I get the cool job and get to do what I want.

So when I woke up at three minutes past four that sunny Tuesday morning I knew that In should either roll over and get some more sleep so I could work late that evening, or that I ought to hit the books for a bit before class. In the end though, I did neither. I got dressed, slipped out of the dormitory, shoes in hand, and headed for the portrait hole.

Part of being me is the water thing. I can't help it. Being away from water for me is like the worst case of dehydration you can imagine. Even being on dry land for just the last two weeks had already brought me out in spots and a permanent headache. I kept having dizzy spells, my hair was greasy and my eyes ached when I shut them like my tear ducts weren't producing enough liquid to lubricate them.

So at a little before four fifteen in the morning I sprinted across the grounds, kicked of my shoes and dives head-first into the cool water. Imagine having been living in the jungle for a year, without being able to wash, or clean your teeth, then being offered a long, hot shower with shampoo and soap and a warm towel for afterwards. That is what it felt like diving into the lake. I could almost feel all the impurities in my body flowing away.

I often wondered, at times like these when I was just floating, what would happen if I couldn't get back into the water for some reason. Would I just dry out like a jellyfish left out in the sun? Would my skin shrivel like a figs or would I simply evaporate like so much hot water?

For a while I just floated, letting the currents pull me around until my head had cleared. I opened my eyes and began to swim. A couple of Gringylows were nearby, their voices high pitched. I listened to them for a while but soon moved on as they were speaking far too quickly for me to gather anything of their conversation other than that 'They' were coming. Deeper down, the weeds were thicker and when I spotted the end of the rock face and the steep dive down to the very centre of the lake I didn't even look behind me before kicking my feet free from the last of the weed and angling myself downwards.

I told myself afterwards it was the voices I could hear ahead that made me go deeper with such reckless abandonment. I knew full well though that it wasn't. I was intoxicated down there, giddy with the freedom of being alone and able to do what I wished, free from the restraints that a normal human would have.

The voices were high, haunting in their capacity and as I swam forward they grew stronger, drawing me closer. I knew where I was going now. I'd been this deep only twice before and both times I'd seen them. The first time from a distance, the second, far closer up.

The mer surrounded me, their yellow eyes and broken teeth glinting slightly in the gloom. Up close to them, I could see how their environment had adapted them to be the perfect predators and I felt clumsy, like a baby trying to run before it could walk. Underwater my body adapts to help: my pupils become larger, almost blotting out my irises so I can see in almost complete dark. My feet lengthen and flatten slightly and small webs grow between my fingers. Slashed gills appear on my neck but the biggest changes are the ones I can't see. My lungs harden, my bones become more flexible so the pressure doesn't kill me.

The mer are beautiful though, in an unearthly, scary sort of way.

One of them approached me. A male, he must have topped seven feet and had a long grey-green beard floating in front of. His yellow eyes took me in for a moment then he gestured to the my escorts who, with a flick of their powerful tails, vanished into the darkness. I looked at him and I realised that he must be their leader as a band of string and small stones encircled his head and the spear in his hand was larger and more deadly looking than any the others had carried.

"Come." His voice was harsh against the silence of the water and smooth somehow too. I didn't know if he was speaking English or if I was understanding Mermish as easily as I could understand all the languages under the surface and it didn't matter really. I went with him. It never occurred to me to be afraid, I instinctively knew he would not hurt me because, human as I was, I too, was a little like him.