It screamed.

Of course it screamed as the knife severed its shoulder. A tiny hand attempted to grip his finger. He detached that arm too. Little legs kicked and were removed and jointed and added to the cauldron. Snape strode to the edge of a clearing and ran his fingers down the trunk of a juniper. A whisper opened a wide, lens shaped wound, into which he inserted the still screaming, mutilated body. A squirt of potion and tiny rootlets began to form around where limbs were missing. As they began burrow into the host tree, he returned to his cauldron.

There was no easy way to kill a mandrake, if the flesh was to remain useful.

There were ways around a shortage of material; even if it meant brewing for eighteen hours straight.

The sun was visible in the circle of blue above him by the time he'd finished and flasked the Mandrake Restorative Draught. It was, he realised, a little after noon. On the northern edge of the clearing a ridge of granite broke from wood sorrel and lesser celandine. Snape sat down and unwrapped the parcel the house elves had prepared and pulled a bottle of ale from his potions ingredients case.

With a breeze singing in the branches above and sunlight spotting and rippling on the forest floor, the Forbidden Forest seemed strangely peaceful. Or perhaps it was just that he'd completed his task. Snape vanished the remains of his meal and got up to examine the juniper that now resembled a python shortly after feeding. It would be a few days before it looked normal. He peered into the closing gap in the bark; the imprisoned face was peaceful. Light-headed with exhaustion and slightly drunk, he attempted Legilimency. There was a thrumming that was more than wind in the branches and, for perhaps the first and certainly the last time, the mandrake's eyes opened. They were a clear green.

-

Snape didn't know if the ordinary trees in the Forbidden Forest moved. The ones containing mandrakes certainly did. Over the years the clearing grew wider. Had he not once seen unicorns drinking there, he might have been uneasy. Instead the area became his apparition point and, later, a place for many things of which the Dark Lord would definitely not have approved; his refuge from a world in which he was a stranger. While the centaurs, had they chosen, might easily have put an arrow through his back, things like Acromantula were less trouble in the open. In retrospect, it was easy to deduce that Hagrid had discovered his continuing use of the clearing and Hagrid, of course, could not keep his mouth shut.

'Legilimens!' howled Potter.

Snape was sprawled on his back in the mud, missing his wand, half of his right hand and part of his jaw and strongly disinclined to oblige the little toe rag.

'Sectumsempre!' followed, further ripping his clothes, chest and his abdomen. 'Sectumsempre!'

Snape was a bloody rag rapidly becoming one with the earth beneath him and now the trees were moving in, getting nearer, snakelike roots wrapping around him, pulling him under. He could see Granger, shaking, white, struggling not to vomit. Meanwhile, Weasley was attempting to restrain the hero. 'Harry! Harry?'

Muddy red liquid poured into Snape's nostrils. He choked and forced his head up.

'Avada Kedavra!'

-

Leaves fell through soft light, covering the forest floor with gold and red while, in the cold darkness beneath, Snape struggled to remember. As frozen winter set in, high above, bare branches sang siren songs of sleep and dreaming but still there was something that would not let him rest. The year turned and the ground grew warmer. As his body began to dissolve, still Snape puzzled until, at the first fragile greening of the branches above, it came to him: the thing he had been shown and then commanded to forget: there was a thirteenth use for dragon's blood.

It was a simple potion: the other main constituents being mandrake root, mistletoe, phoenix ashes and living human flesh. By the fitful light of cauldron-fire, Flamel adjusted the tourniquet on Dumbledore's upper arm. As the blade would cut through stone like butter, the removal of everything below the elbow had been almost unfelt. 'It's a pity that there's nothing to reduce the pain that won't interfere with the regrowth,' he said handing Dumbledore a roll of leather to bite on. 'You obliviated them?'

'Only James Potter saw how much of him was missing.' Dumbledore stuffed the leather into his mouth and bit down.

Flamel turned and strode into the shadows by the dungeon wall, where a bloody sheet hid something on the workbench. It shone red and black as he raised it. 'The entire body cavity's been emptied,' the alchemist remarked. 'Lupin will know he ate something. I suppose you're going to tell him it was a cat?'

Dumbledore nodded, sweat dripping off him.

Flamel dropped the sheet. 'I'm helping you cover this up only for the sake of the school,' he said.

'I'll make it up . . . '

'How will you make it up to Snape?'

The memory ended. That, Snape decided, would explain many things. He needed his wand. The roots that grew though him began to search for something more than nutrients and water.

-

Disturbed only by the increasing warmth and the occasional questing insect, it was peaceful in the darkness of the leaf mould. Still there was a waiting; a knowing that her chosen one, her wizard, still needed her. As the days grew longer, it came to her that once she too had grown strong in the light and air. It wasn't so difficult. Pale filaments slid down through the tender earth. A slim shoot climbed and broke the surface, formed leaves and lengthened steadily while, below, roots tangled and wove an enchanted web beneath the ground.

Fed by magic, entranced by rain and the sweetness of sunlight and the feeling of something beloved growing strong within her, at midsummer she knew it was time. Something neither exactly fruit nor bud began to form just above the ground, black and sticky and burgeoning. Warm days passed and by the end of July it was ready; the midnight green and silver carapace split and something long and pale appeared, swelling and unfurling from within it, becoming taller and ever more human in shape. The birch tree that had once been Snape's wand swayed in the summer wind. In her shadow, an arm pulled free from its wrapping with a sound like tearing paper. Long fingers plucked at integument freeing the other arm, more fingers, a wand. As the membranous relics of his resurgence fragmented and blew away, Snape smiled.

-

The Mark was only a physical expression, a sign and minor tool of the Dark Lord's mastery. The real magic ran much deeper. Voldemort had no fear that his servant would betray him and was amused and pleased by Snape's report. A weapon like Snape would prove useful.

Harry Potter was no longer a threat. He'd been summoned to the Ministry on his eighteenth birthday 'to receive some papers held in trust until his Muggle majority' and been handed over in return for some promises that the Dark Lord might, or might not, keep. And, since this has happened only a few hours before, he was still in a fit state to appreciate the news. Lord Voldemort had the 'Boy Who Lived' dragged before him.

'Now, Severus, as I have no further use for the fool, you may do what you will with him.' Voldemort had already become bored with the boy and was interested in seeing what Snape might achieve. He came down from his throne to observe more closely.

Snape put an arm around Voldemort's shoulders and a hand over his heart and then there was no time to react before Snape's lengthening fingernails were twisting between his ribs and through his heart into arteries and veins. The Dark Lord's mouth opened but no sound emerged, only branches. Leaves sprouted from his fingers and every orifice.

A few ineffective Avada Kedavras caused Snape to roll his eyes. 'The elite,' he scoffed, 'the very "Cream of Magical Society" and you don't know that it doesn't work on plants. Oh, yes. Reparo!'

Harry stared up through mended glasses.

'Potter,' said Snape. 'Probably a good time to leave. And I'll ask you to deal with the Horcruxes. You should have awhile; Riddle's not going anywhere as long as I'm alive.'

As Harry watched, roots began to spill from Snape's boots, burying themselves in floorboards that were looking more and more rope-like, becoming part of Snape who was getting taller. When Snape pushed aside the wall, Harry could see some of the Death Eaters, the more sensible ones who had run, out in the ruined garden and they too were changing and becoming part of the landscape. Closer to hand, Bellatrix Lestrange was a small holly bush, trying vainly to root herself in the marble of the throne's pediment.

'How?' asked Harry and then Snape was in his mind showing what had happened years ago; what was happening now.

'The Great Forest isn't gone,' Snape explained, 'and in places it still overlaps with our reality: in public parks and private gardens, on wasteland and in nature reserves, even alongside roads and motorways. When Muggles find themselves wondering why they're in Southampton rather than Solihull, it isn't always because they didn't read the signs. The connection has been strengthening for centuries. Muggles aren't frightened of forests anymore. The silly buggers want to protect them.'

In Surrey, and on live TV, a roads protester fell from a tree and floated to the ground as gently as thistledown.

All over the country, trees began moving very, very slowly away from walls and into sunlight.

It stopped after about a week but by then the muggles knew all about magic and they wanted some too. There were protests and 'Party Political Broadcasts' and 'Committees' and, after a very drunken quantum physicist told a chat show host that he could see no real reason why not, ever vaster amounts of funding.

-

There are new houses down where the stream's been dammed to create a small lake.

Within the old, stone walled gardens of the Riddle Estate, thickets of rhododendron and azalea compete with wild roses and buddleia while white beam and aspen, oak, birch and rowan sway gently. Beyond the walls is the ancient Great Forest and sometimes Little Hangleton. The Riddle house itself is rubble; a birch tree quietly strangling a small yew in one corner of the foundations. The children have strung a hammock between the birch and some ironwork that had been part of the building's exterior and a pair of red-haired sylphs are swinging merrily in it.

'Down will come baby, cradle and all', says Harry reaching out to his children and opening his mind.

'Ah, but then I'd have nothing to look forward to,' replies the tree.

'What about . . . ?' Harry indicates the yew.

'Tom's had a change of heart.' A zephyr catches the column of leaves turning it to shimmering silver. 'No worries.'

Snape's hatred of Potter would not have survived his metamorphosis, even if he hadn't already reached his own conclusions about the boy who lived to be a distraction for the Dark Lord. Dumbledore's specially edited version of the prophecy had been entirely misleading.

Hermione thinks she know and spends many hours on a picnic blanket in the little suntrap of the walls with Radio Four playing quietly. Sometimes she reads aloud from potions journals. She is particularly proud of her own work. Hermione does this because of what she thinks she knows that Snape knows and doesn't want Harry told.

Snape quite enjoys the sound of Hermione's voice but is usually too busy doing interesting things involving carbon dioxide, water and various trace elements to take much notice. Sometimes Luna and Ginny sit with Hermione.

Luna and Ginny really do know.

Luna and Neville had brought Ginny up here to explain their observations and deductions concerning the 'Boy Who Lived' and they had all decided that what Harry didn't know wouldn't hurt him. After all, Harry was very, very different from Snape, had been only a baby when it had happened and was, very obviously, apart form his mysterious survival, quite normal.

Neville enjoys a 'nice little chat' while working in the garden and has quite a bit to say to the birch which he is especially assiduous in caring for. (Certainly there has never been any shortage of organic fertilizer).

'You've gone soft, Snape,' says Potter, laughter sparkling in his clear green eyes.

High on sunlight, the birch does not reply.

-

Thank you to everyone who reviewed. I hope this makes more sense.