Staccato cracks of lightning and the tumbling bass of rolling thunder warred for supremacy in the night sky. Their battleground stretched from horizon to horizon, as far as the eye could see. Clouds hung low and close where they could be discerned through the rain-soaked inky blackness. Fitful flashes of light, way up in the heavens, danced behind this thick blanket, partially hidden from view as if seen through smoke-stained glass. It was just enough light to set fire to the driving rain and sleet, turning the droplets intermittently into tiny burning crystals hurtling towards the earth. They threw themselves into the ankle-deep water that now pooled above the muck and slush that had been a meagre yard. When the door of the adjacent hovel was flung open, they dashed hungrily into the abode, leaping across the threshold and stretching ever further, in their growing numbers, into the room.

And all the while, the clouds grew thicker, and the heavens seemed to close in.

A whip-crack of lightning so loud as to send a man staggering illuminated the cause of the battered door. Two figures struggled against one another, in a desperate melee. They slipped and tumbled in the mud. They grappled and grunted and howled to the merciless night who tore the screams from their throats as soon as they were uttered. It was hard to tell from the ferocity of the rain, but it appeared a touch of red began to mingle with the brown at their feet, mashed and swirled in the mud like some artists' mad creation.

Suddenly, a flash of light from the ground this time, and one body flew towards the house. It ragdolled through the open door and crashed to fall still in that puddle of growing rain.

The clouds rumbled their displeasure, and the second figure leapt through the opening, bundling up the body and slamming the door shut in one movement.

Outside, the rain continued to hammer down.

The sudden stillness caught Harry Potter by surprise, and the half-second it had taken for him to adjust had almost cost him. The figure in his arms gave a mighty surge, and broke one arm free. It battered Harry's face and head, tore at his clothing, wrenching free a small bundle of sodden greenery that splashed to their feet, instantly trod into the mucky water as their awkward bear-hug of a dance continued.

Just a few minutes… more.

Without warning, the figure in his arms let loose a cry of the dying, and a fiery outburst tore forth from his breast, knocking Harry back, searing away all water in the room instantly, and leaving a charred black scuff on the floor where his greenery had fallen.

The figure stilled, drew one shuddering breath, and collapsed on the tiny cot in a tumble of arms and legs.

Once again, it was over.

But for how long, this time?

In the moment's reprieve, Harry drew his wand, tending to the scratches and cuts that the fight had left him with. The clinging mud he scraped free by hand. He made sure the figure on the bed wasn't too uncomfortable, and took a half-step back – it was all the tiny room would allow – to take a seat on the only chair. It groaned a warning as he lowered his weight.

He stretched a stiff leg, aching from a long walk over rugged terrain, and came into contact with the wall opposite. He rolled his shoulders, to loosen muscles tense from hurrying across an entire island with a time bomb of a wizard as his only company, and his elbows brushed the dirty walls. There was no source of light, save for the occasional flash of lightning flaring outside. But he could see well enough. He could see the stretching shadows looming in every corner, and the way they groped forward for every inch of ground they could take, fleeing only reluctantly when the lightning burst. The moment it was gone, they were back again, eager to claim more and more of the tiny space, encroaching in Harry's periphery everywhere he looked.

A violent gust of wind made the whole structure shudder, as if suddenly repulsed by its inhabitants. The rain that lashed the rooftop began to find ways through the shoddy roofing, adding a steady drip, drip to the orchestra of the night. Where the water pooled near the edges of the room, the shadows reached out hungrily to lap it up, growing their territory and making the room seem smaller by the minute. No, not a room. Not even close.

This was a cell.

Eventually, his partner woke, and Harry was there to offer him support. He gently eased him to a sitting position, and trickled an Aguamenti Charm between his lips.

Dull eyes scanned the room. There was that flicker of familiarity as they noticed Harry. They darted to the floor, a single white petal lay, fringed with ash.

'So much for our gardening trip.' His voice was dust on the wind.

'Not like we'd have used them anyway. We were seen, that's the main thing.'

'Damn right we were seen. Had to go and punch that Muggle, didn't you.'

Harry just grunted. Damned kid with his thick hood and thick skull. Just because he'd been holding a knife didn't make up for a lack of brains.

They paused for a moment. His companion signalled he was fine, and levered himself more upright, away from Harry's support. The exertion clearly pained him, and the stretched, cracked skin of his neck showed a fluttering, feeble pulse. With the effort came the release of his last hold on the disguise he held. Hair returned to its normal sandy brown, eyes from a deep brown to a milky hazel. A dusting of stubble appeared, and the skin grew taught and grey and sallow, casting long shadows beneath prominent cheekbones.

'Welcome back, Teddy,' Harry breathed.

'It's getting harder every time.' There was a pleading tone in his voice.

'I know. But what choice do we have?'

The long pause that preceded his words warned Harry exactly what was coming.

'Hand me in.'

The curtain of their room – rotten rag that it was – had been burned away in the brief rush of flame. The ill-fitting pane wept rain all around its edges. Harry stared hard out into the night. Because he couldn't look at Teddy as he answered.

'We can't. They're hunting you. Day and night they tail me, and they're getting bolder. They say that the Steelhearts were aptly named; I don't want to be the man to find out.'

Even with attention fixed out the window as it was, Harry noted the falling of shoulders. A gesture of defeat. Of betrayal. A piece of himself deep inside cracked when he saw it. Not broke, not yet. He had duties to fulfil, and so he would hold himself together, for as long as he could. But the sigh that escaped Teddy Lupin's lips signalled the first rain of dust shaken loose from failing foundations. It shook Harry Potter's night more than the loudest thunder.

'The longer we play this game, the more likely we'll be caught, Harry. Even I know the Ministry has outlawed what we're doing.'

'Because they are afraid. Because they hope that hiding behind desks will leave them out of sight and out of mind. Because they think that eyes looking elsewhere at the moment means that they are forgotten. They are wrong.'

Teddy shook his head, wiping away the layer of spattered mud from his face. They had both fallen to the ground amid their scuffle. Rolling in the mud like children. Like enemies.

'And what if I don't want to do it anymore? What if it's too much? Too much pain, and terror, and I'm just. So. Tired.'

'I wouldn't ask this of you if it wasn't important.'

'Is it, though? How can you be so sure? "They are wrong. This is important. Harry Potter is right." These things you state with such certainty, as if that makes them true. Truth and certainty are not the same thing. Make sure you remember that. Not all of us have had the benefit of living a life so just that our conviction is immune to faltering. Voldemort was certain he was right, after all.'

Teddy's words stung, but Harry weathered them, as he deserved. A little more mortar shook free from their shared foundations.

'I trust my instincts. They've won me one war already. All I ask is that you have a little faith in me in return.'

'There's not much left, Harry. I'm tired and scared. I'm not getting any better, the episodes are getting worse. I'm scared I'm going to die here, in this prison cell of a room.'

This time it was Harry's turn to let out a draining sigh. It felt like he gave all the breath he held in his lungs along with it, and a little bit of himself he couldn't quite get back.

'You know as well as I do they'll work it out straight away. If they find you, they find out. They will know where it all started, and why it all started. And then they will come for us. For now, the instructions are clear. We carry on.'

'There you go again, the instructions. The missives, the secret letters and owls at all hours of the night. The errands across the country and the world to who-knows-where, chasing smoke and mist and a noble death. At the behest of Merlin-knows-who. When the dust finally settles, what will they say of us? Of you? Will the Chosen One have undone his legacy by plunging the Wizarding world into war? Whose side are we even on?'

Harry stood up, tired to his very bones all of a sudden. Again, they had fallen into the tread of an argument they had nearly every time they met. Teddy was trapped here day and night, he had all the time in the world left with his thoughts, and they were growing ever darker. They clasped forearms wordlessly, and at the door Harry turned to favour Teddy with a lasting gaze.

'Someone needs to act, Teddy. If not us, who?'

The crack he made as he Disapparated was lost in the fervour of the storm.