From the Journal of Nymphadora Tonks

I sensed it like a barometer senses rain. I saw the signs: his reluctance to talk, his frequent sidestepping, and the return of his reserved and guarded appearance.

I felt sad. Sad because I'd never really known him. He never gave me the chance. I knew he wouldn't, yet for some reason I persisted. I persisted because, at the time, he was my only option – my only prospect for tenderness, sensuality and affection.

When it began, Remus had been gone for over two months, and I still couldn't eat or sleep properly. I would often cry myself into disturbed sleep, and I was desperate to replace the feeling of rejection with anything I could stake claim to.

Severus had been there on that first night of the school term, apparently as lonely as I, concealed behind high walls, hiding his poor heart from the cruel world surrounding him. I saw that. I saw a vulnerable man in need of love. Except that he didn't know he needed loving. I eventually came to realise that I could not offer it, even though I tried.

It began as a distraction from the pain; a way for me to feel attractive again, an opportunity for me to experience an emotion other than loss and rejection. The first time, the sex was angry and needy, and I hated myself for it. I used him. I used him to kick-start my life, to try and find myself again, but I was struck down with self-loathing. I had betrayed Remus and my love for him.

I didn't blame Severus. I blamed myself. But when he mistakenly believed I was pregnant, I lashed out at him. I thought he would never understand how I felt.

That changed on Christmas Day. Severus was so gentle. He reawakened something inside me, and I started to yearn for his touch, the feel of his lean, naked frame lying on top of me, the tickle of his hair on my face, the warmth of his lips on mine.

Somehow, my guilt lessened that day.

But when Severus arranged the lease on the apartment above Zonko's, I began to feel trapped. I was too weak to argue and hated myself for being so easy to manipulate. Yet I still felt gratitude towards my benefactor, and I thanked him the only way I could – with my body.

I don't know if he ever realised I hadn't reached climax during our union in the dungeon. The whole thing was for his benefit alone.

When I was late for Slughorn's New Year's Eve party, Severus took me by surprise in more ways than one. He seemed angry with me, and I still don't really know why. I'll never forget the side-alley of the Three Broomsticks. He scared me and aroused me all at the same time. Danger was thrilling.

After he'd stayed the night and attended the Death Eater meeting, he returned to me once more, and I then began to realise that I might need more than just sex. I needed connection. Something more emotional. Something to replace Remus.

And then I saw Remus again, at Grimmauld Place, thinner and shabbier than ever. My nurturing instincts overrode everything; I wanted to take care of him, help him, heal him, love him. But he rejected me again. His words humiliated me.

I ran back into Severus's arms.

I cried myself to sleep every night when Severus was not there. He was a temporary fix to my despair. During this time, I noticed a change in him, too. He became colder, more distant. He started to retreat into himself. At first, I thought he was jealous. Maybe he was. But he insisted he was emotionless. I didn't believe him. I had seen feelings in him. Things he didn't want to admit.

I tried to coax him, but he became increasingly cagey. Eventually he simply stopped answering my questions. I knew he was slipping away. Desperate, I held on to him tightly, but the stronger I held him the faster he slipped, until I knew the end was near. I didn't want to believe it... but still, I knew it. Deep down.

It was the first of March. Ronald Weasley lay in the hospital wing, recovering from his dance with death after swallowing poison from a bottle of mead intended to reach Dumbledore. When the Order convened in the Headmaster's office, Severus appeared preoccupied and withdrawn. He would not meet my gaze. I thought he had been affected badly by the latest casualty.

Severus arrived at my apartment shortly before midnight, Apparating straight into my bedroom, where I lay in bed, waiting for him. I cannot say how I knew he was coming. I just did. The air seemed heavy with the promise of thunder. Not the meteorological kind.

Dark shadows streaked the room as the light of the full moon shone through the window pane. I could see the blazing, malevolent look in his eyes. I wasn't scared. I had a sense of inevitability about what was to come. I knew it would be fierce and intense. And I wanted him inside me, one last time.

Severus slung his cloak and frock-coat onto the bedroom floor, ripped open his trousers and straddled me, inching further and further towards my head. He took his swollen erection and pushed it into my mouth. I almost gagged. Trapped beneath his knees and the bed sheets, I wished I could Metamorphose to take him whole. But I still had no command over my abilities. So I ran my tongue around his bulging member, sucking him until he almost came into my mouth.

He pulled out at the last second, panting and growling, and then he ripped the blanket from the bed and took me, already soaking wet, in one swift movement.

I remember the feel of him inside me. Hard and whole, awakening my body, enticing me to feel. And feel something I did; it was like it always had been between us, but this time with a rougher edge.

I knew we were together for the last time.

I knew that after this moment it would be over between us. Our arrangement, and whatever attachment we had or had not formed, would be gone.

I clung to him, gripping his buttocks, encouraging him to plunge deeper and deeper, until I climaxed with a rippling, tingling, back-arching shudder. He continued to thrust into me, rougher and rougher, until his orgasm exploded inside me. He growled, almost shouting out. Then he collapsed into a heap on top of me.

His behaviour changed within seconds.

He withdrew from me, turning away to sit on the edge of the bed. I held out my hand to touch his arm, but he shrugged it away, and he stood and buttoned up his crumpled attire.

I watched him, black and white in the moonlight, his tall, slender silhouette imposing and rigid, lurking in the shadows of the room. Soon he was fastened up to the neck, confined by his oppressive clothing, lingering at the foot of my four-poster bed, a look of pained embarrassment on his features. It was strange to see his feelings in direct contrast to his tightly-fastened robes. But it wasn't long before he restored his mask and blinked the emotions away to reveal his usual pale, thin-lipped face.

His words, however, took me by surprise.

"I'm sorry," he said.

I wasn't sure if he was apologising for the rough, dominating sex, or for the abrupt ending. Either way, I knew our relationship was over.

I got out of bed. The length of my black nightdress fell back down, covering my body like a shroud.

"I'm sorry, too, Severus."

And I meant it.

I was sorry for using him to replace my lost love, sorry for hoping he would eventually feel something for me, sorry that I never really knew him.

I don't know how he interpreted my apology. He nodded once and Disapparated.

Weeks later, I descended the stairs to the dungeons at Hogwarts, desperate for news about Remus. I had hoped to speak to Dumbledore, but found the Headmaster was absent again, and I was so worried that I even asked Harry Potter if he'd heard anything. But my search for information came up with nothing, and so I went down to see Severus and ask for his help.

Severus did as I asked, and he returned two hours later with confirmation that there had indeed been a werewolf attack, but it had been the Montgomery family's misfortune, and Remus had not been involved.

Remus was still alive. There was still hope.

That was the last time I saw Severus, until the death of Albus Dumbledore.

I caught sight of him when he arrived at the Astronomy Tower in the middle of the battle, and I watched him leave shortly afterwards with Draco Malfoy, and the Death Eaters in pursuit. I had no idea what had happened, and I let him pass without question.

When I heard of his betrayal, I couldn't believe it.

People were quick to point the finger; the evidence seemed to condemn him as a murderer, but I found the whole thing hard to grasp. The Severus I knew would never be as cold and brutal as to kill a weakened Dumbledore begging for his help. It seemed so... out of character. But as I listened to others' tales of his treachery, I had to concede he was a killer. How could I not?

It was, of course, the death of Albus Dumbledore which brought Remus back to me. He caved in, that night in the hospital wing, at Bill Weasley's bedside.

And for a time, Remus and I were happy. After the wedding, I quickly fell pregnant and I thought our world was complete. But then Remus retreated again.

As I sit here, alone at my parents' house, hoping and praying that he will come back to me and help to raise our unborn child, I wonder if I was right to have told him about Severus.

If I had kept our secret, perhaps Remus wouldn't have left, and I wouldn't be facing single parenthood and a life without love.

I also wonder if the popping sound I just heard was a Muggle exhaust-pipe or Remus returning to me. Mum and Dad aren't due back home for hours.

Who would I prefer to see walking through the garden gate and up the drive?

Will it be a man in dressed head-to-toe in black, his long cloak rippling in the wind, and his dark, hooded eyes promising an explanation for his duplicity?

Or will it be my Remus, scruffy and tired, saying he's sorry and telling me he's ready to be a father?

I see a wisp of brown and grey hair in the distance and suddenly my heart leaps.