My gorgeous, perfect companion, and I didn't know if I would ever see her again.

I turned. Facing me in the doorway, as I knew he would, was James Ripley, his shotgun rested menacingly on his left arm. Once more, he fixed me with that look, devoid of anything but hatred, his eyes blazing and his mouth fixed in a grin of utter loathing.

"Who the fuck are you?"

"I'm Harriet," I replied. I tried not to, but the words flowed from me before I could stop myself. Curiously, fear had long since departed, to be replaced by weary resignation, and yet I couldn't prevent my tongue from following the well-worn track of this conversation, despite the knowledge of where it would lead. "I wish I could explain 3;" I knew I couldn't, I knew I wouldn't, but the unyielding tracks of time impelled me.

"Jesus Christ, don't even fucking try. God, I've seen it all now. All this time, there was me thinking it was a man 3;"

"What?"

"'I'm Harriet, I'm Harriet.' I'll bet you are. And we all know what Harriets do." Just as it had before, Ripley's temper steepled out of control in a matter of moments. He edged forward, his gun barrel twitching up and down uncontrollably as he circled around me. I wished I could fight back, but I knew it was useless: I couldn't fight time and I was destined to meet the same fate I always had. My only fear was that this time I might not escape; that this time the violence would escalate.

Ripley advanced, his face red with fury and a long, ugly vein pulsing the length of his neck. Even then - his expression contorted with hate - I could see he was an attractive man: there was something of Jane in him - the flare of the nostrils perhaps, or the line of his cheekbones - and I could see why Mary Ripley might have been attracted to him. Now, though, I was confronted by a man consumed by hatred, a man who eschewed understanding, displayed no capacity for compassion. He twisted the shotgun in his grip, right hand menacingly on the trigger, his eyes wild and unfocused. Still, though, I felt no fear - and that was strange. Always, at this moment, I had been transfixed by terror, but now I felt calm.

And then a glorious, liberating notion struck me: time isn't solid, it isn't an unyielding track at all. It meanders, it shifts, it diverges and merges, it flows like the river downstream to the sea. You know its destination, but cannot predict the course it will take: it only needs a gust of wind, or a casual pine cone thrown from a bridge into the foam of the current, and its track is altered. Altered by the merest fraction, but in that fraction everything changes.

"'What on earth are you doing with her?'" Mary Ripley's words struck at me like a lance as her husband approached. Those words were different: time had changed. The past had changed.

And that meant that I could change time. Couldn't I? I wasn't, after all, harnessed to an unchanging rota of history.

"Tell me you aren't!" Ripley screamed at me.

I was ready for his retort, and my reply flew unbidden from my mouth: "Yes I fucking am! And what of it, you bastard?"

We both halted, shocked by the violence of my response. For a moment, nothing registered on Ripley's face, and then it was overcome by an explosion of rage. However angry he had been in our previous encounters, the fury which now engulfed him was of an entirely new, and acutely increased dimension. I knew I was in danger. Reaching to the fireplace, I grabbed the metal poker and rose, brandishing its sharp point at him. I swung and made to hit him, and he ducked to the right, bellowing with anger. My earlier clear-headedness had gone, leaving me once more in the grip of naked terror. Ripley was hunched over the fireplace, staring up at me, his shotgun cradled in his arms. I heard the click of his safety catch being released and rocked back in alarm: by changing the course of time I had no idea what I had unleashed, nor what fate would befall me, and as I stared into the blank, frozen eyes of Ripley I felt certain that I had engineered my own death. He was panting heavily, sighing as he swung the shotgun towards me, his eyes fixed on mine. Instinctively, I swung the poker with all my strength, gripping it in both hands, and slammed it hard against the barrel of the shotgun. Pain sheared up my arms as metal collided with metal, the handle of the poker seeming to slice through my fingers as it recoiled from the impact and reverberated mercilessly in my hands. It had the same impact on Ripley and he yelled, dropping the gun and shaking his left hand furiously. I advanced towards him, my poker raised. Unprotected, he looked at me desolately, the animal hatred in his eyes finally tempered by fear.

At that moment, I had no idea what I was going to do next. Was I going to hit him? Had reality shifted so much that I could be driven to violence? Adrenalin was surging through my body, a brute energy which both thrilled and appalled me, and I fancy, then, that I was capable of anything. As we stared at one another, I could feel the transfer of power from Ripley to me; I could see in the withering of his frame, the defensiveness of his posture, that he was ready to submit.

And I have nightmares, even today, about this moment. Could things have turned out differently? Would the pain that was yet to come have been averted if I had acted when I had the chance? I wish I knew, but then again, what does knowledge offer - without recourse to action - except the pain of conscience?

My moment was lost when Mary Ripley entered the room. She screamed and I started, looking towards her in alarm. Ripley, calmer and stronger than me, took advantage of the distraction to grab at the poker and he knocked it from my hand. It fell to the floor and he swooped with remarkable agility to pick it up. Mary Ripley's screams still filled the air, a piercing, terrified wail, so shrill it sounded like a whistle. Ripley shaped to hit me, feinting with the poker, and I skipped towards the door, but with Mary rooted in the doorway I had no means of exit. Realising this, Ripley darted towards me, brandishing the poker like a master swordsman, and I slipped behind his armchair, trying to put an obstacle - any obstacle - in his way. It was a mistake, and I was now cornered, with Ripley between me and the door. I backed away, my legs shaking and my stomach heaving, an icy sheet of fear washing down my face. There was a scrunch of breaking glass as I stood on one of the photographs Jane had dislodged, and I looked down at a picture of Mary and Ripley, arm in arm, smiling into each other's eyes: a beautiful picture of a beautiful couple. Except that now a jagged shard of glass scored across the picture and appeared to slice through Mary Ripley's heart.

My ears were pounding as I retreated to the extent of the room and felt the wall, unforgiving against my shoulders. I shrank backwards, my body attempting to inhabit an ever smaller space, and watched Ripley approach, my legs buckling, muscles tensing against the inevitable blow. I felt curiously ambivalent at that moment, both resigned and fearful, resentful and fatalistic. Clasping my hands to my head, I curled myself into a ball and rolled against the wall. For a second it jarred against my hip, a disdainful barrier to fanciful flight; but then, bizarrely, it seemed to stretch, become elastic, yield to my protestations for relief. A familiar dizziness overwhelmed me, my legs becoming numb below the thigh and my head feeling detached and empty. I looked around the room, at the Ripleys, at the alien world into which I had blundered. Space began to lose its meaning, the furniture melting into random shapes, governed more by colour than by form. I was losing control - losing myself and my grip on the room, my grip on reality itself. Consciousness began to slide from me. In a haze, I saw Ripley before me, his poker raised, ready to strike, but with a look of bafflement on his face. Behind him, Mary was still screaming, her hands covering her eyes. I waited for the blow, waited for Ripley to exert his power over me, and I felt the doleful ache of hopelessness: the saddest moments in life are those which you can predict but can't prevent. Ripley was towering over me, so large he must have been a giant, and the lifeforce began to drain from me. My vision was blurred, my thoughts confused, and the room shivered and became insubstantial. In front of me, Mary and Ripley seemed to stretch and merge, they became an amorphous blob of colour filling my vision, invading my thoughts. I tried to focus but lost control, found myself sliding into ethereality and doubt. Reality was lost, pulsing gently with the ripples of time, and I was enveloped in blackness.

On to part thirteen