In the Dark.

Mordred pulled the t-shirt off over his head and threw it into the locker. The response gear wasn't comfortable. It was worse under the kevlar body armour he'd have to stick on in a few minutes but he'd adjusted to the set up.

'Cool tat.'

'What?' He turned to the voice and saw Will, already dressed, stood by the door with eyes trained on his chest. The exposure made his skin tingle. 'Oh. Thanks.'

'What does it mean?' he asked and stepped in, door clicking shut behind him. Will's disguise was good as always. Mordred had noticed how his whole manner changed with the clothes, the cockier movement in his shoulders, his legs standing wider apart, northern accent easily believable. It was dark, tough, and blended in perfectly with the illegal firearm trading he'd managed to lie his way into. They'd done what normally took a year in about two months and it could all blow up in their faces if they didn't get it perfectly right in three hour's time.

'Nothing,' Mordred said, grabbed the shirt and pushed his arms through the sleeves. He ducked his head down and through the neckline quickly.

'Come on, man,' Will scoffed and moved to lean against the closed row of lockers next to him. 'Don't give me that closed-off mystery shit.'

He smoothed the shirt down, ruffled his hair back into place, and closed the locker's door. 'It means you can't escape your past.'

Will lifted one eyebrow. 'Dark times?'

Mordred grabbed his bag from the changing room's bench and grinned at his partner. 'Everybody has them.'

'I'm a light-at-the-end-of-the-tunnel kind of guy myself,' he said and started back to the door. 'You looked swanky last night by the way.'

'You were there?'

Will opened the door for him. 'God no, but Freya was and she bombarded me with a live documentary of the event. If she weren't already in police surveillance I'd suggest she go into photography.'

'Freya?'

'Jealous?' he asked as Mordred passed into the quiet hallway. The building's changing room, showers, and whatever else were kept in the first level of the basement. Their path back up to the van was well lit and cold.

'Of what?'

'Totally believe your act,' Will assured him with a wink. 'Anyway, we've got to figure out a game plan for Kestrel's big moment. My arse is on the line and it's your job to take good care of it.'

'I thought it was your life.'

'One can't exist without the other, Leir.'

He side-eyed Will as they climbed the stairs. 'We have the game plan already, you know that.'

'Could always spitball a few more alternatives in case, but sure. All we've got to do is sit tight and look pretty then?' he said. They reached the ground floor and Mordred headed to the side-street exit quietly. Arthur's case had kept him up too late over the weekend. That magic had left a stale taste in his mouth. 'You all right?'

'Yeah, just a bit distracted.'

They stepped out into the air still wet with that morning's mist and stopped. 'New lad in your life?'

'No.'

Will watched him thoughtfully. 'Good, it'd ruin our dynamic.'

They shared a final look. This was the part where Mordred climbed into the van and they switched to comms. The part where they couldn't afford to screw anything up. 'If things go south, Leir, I don't want you doing anything that could get us both killed.'

Mordred's stomach twisted. 'They won't go south, Will.'

'I know that, just checking you're not having second thoughts. You're doing that whole distanced thing again.'

'I'm just planning how to best take care of your arse. Thought that was obvious. It's my job after all.'

Will flashed a grin. He was down the street and had mixed in with the passing crowds seconds later. Mordred watched his breath on the November air before he stepped up into the nondescript dark van. Three other Intelligence officers had set up surveillance equipment and the armed response team were already driving to Hackney. He slammed the doors shut and took his seat.

Impressive selection.

Will's voice came through clearly and Mordred wished he could see what was going on in the building. He'd heard the steps, knew they'd gone down under the main shop floor of the Mediterranean groceries store, but he couldn't be sure. Magic was a struggle to use ever since Merlin had been attacked. He'd never forget how painful that moment had been, how he'd collapsed in the middle of the street beside Will. Now it was dampened and it stung to bring that power back to his hand.

If you think that's good you should see what I can do with another week's time.

That was her: the boss. The one they'd been after from the beginning, Kestrel's end game from long before he ever joined the party.

Oh?

This business is generally don't ask don't tell, but why would a handsome young man like yourself need this kind of arsenal?

Offence is the best defence.

Mordred smiled.

I couldn't agree more.

His smile disappeared. There was something beneath her words, something off. Mordred strained backwards to peer over the back of the driver's seat through the window. Two people with cloths pulled up to cover their mouths and noses with hoods up entered the store.

You've had a pat down, Adam?

If you want to cop a feel yourself you don't need to ask. I'm all yours.

Wonderful.

Adrenaline sharpened his movements as he leaned back and spoke through the mic, 'Get out now. They know.'

They had a plan. He had to say the word 'Waltz' to confirm he'd heard the warning.

'Leir, there are more,' Jess told him and nodded out of the window from her position in the passenger seat, magazine in her lap. Three more went inside.

He ran a hand through his hair. 'They suspect him. Someone must have tipped them off.'

'Do we go in?'

Mordred secured the vest around his chest. 'We still don't know who she is. We'll give him a bit longer.'

Find what you were looking for?

Not quite.

Sorry to disappoint. Personally, I find you uncover more about a person when you waltz than you do when you man handle them in a basement.

Mordred relaxed a little but they were still in trouble. The unspent adrenaline was making his muscles ache.

I'll remember that you like to dance, Adam. A good understanding of rhythm is essential to any business deal.

What do I call you, then? You know my name.

Kat.

Is that short for something?

Katja.

Russian?

Slovenian.

I'd never have guessed. Wait. What are you doing? Wait, stop!

Mordred threw the headphones off and pressed down on the radio attached to his vest.

'Go. Cover's blown.'

He jumped out the back of the van to see the response team had already cordoned off the street. The other CO19 officers put their MP5 semi-automatics up and Mordred notched his own securely in place, buttstock pressed against his right shoulder and hand wrapped around the grip. He moved to where they'd positioned themselves around the sides of the main doorway and the lead SFO counted down with his gloved hand. Three. Two. One.

Gunshots, flashes, and shouting had them ducking out the way instantly. Ahead of him the CO19 officers fired warning shots above the stairwell and drove them back. Clouds of dust from concrete and plaster floated into the stairwell and obscured the lower level. Mordred quickly stepped down behind them, gun up, heart racing and eyes searching for Will once they'd passed the dust. They'd blown out the bulb and torches provided poor if sufficient lighting in the basement.

The body on the ground in the middle of the room made his heart stutter. 'Kat' held a pistol out aimed at Will's head.

Mordred moved out in front of the other officers. 'Don't you dare.'

He used his gun to slam into her arm, forced the butt against her nose with a crack, and hit the ground when the shooting started up again. Without the protective ear muffs his eardrums burst in seconds.

He kept low and shouted to the others, 'Back! Go back!'

His authority meant shit all at that point though. This wasn't his job. This was down to CO19 now. They'd fucked it up. It was ruined. They had to get out. Mordred hadn't even taken in the room, the bodies surrounding him, when someone fired a shot next to his head and hands snatched at his body. His right ear rang, deafened and hot, and he swung his elbow back. It hit something and he stamped his foot down on a boot, but it wasn't hard or fast enough. The firing hadn't stopped, they hadn't gone back, Will was down, and then Mordred saw the barrel aimed between his eyes in the shadows. Instinct, magic, surged up in his chest and it pulsed down the inside of his arms, hot and oozing strength.

The screams stole his breath away.

Shots went off in his skull with a sudden painful blistering and then light cracked red through his sight. He crumpled. It kept going, long and undulating, and he curled in on himself, hands around his breaking head. Light turned into blindness and then into a wave of burning sparks that coursed through his nerves, frayed them, snapped them one by one.

'Hey.'

The gentle shaking met with Will's voice and Mordred forced his eyes open. Will helped him back to his feet. They were alone in the basement.

'What happened to you? Mordred?'

'I need to sit down,' he said and started back up the stairs. Half of Will's face was smattered with dirt and he clutched his left arm. One subtle trickle of blood made its way through and dripped onto the ground. 'You're bleeding.'

'There's an ambulance on the street,' he told him softly. 'I'm going there now. You should come with.'

Mordred nodded. 'Yeah.'

Outside they were making arrests, reporters had begun to arrive, and sure enough there was an ambulance providing treatment to an officer. Serious injuries must have been taken to hospital already.

'How long was I out?' he asked Will as they left the store.

'A few minutes.'

Mordred had lost his ear muffs and his gun, his ears ringing painfully. Their van was still parked across the road. 'I'll be there in a second.'

His head spun when he climbed inside and quickly sat down on the chair. Mordred waited like that, calming his breath. He waited for the dizziness to go away, for the sick feeling to melt. He grabbed his phone from the steel table and got out. Will's arm was being bandaged at the back of the ambulance. As Mordred made his way over his chest started to ache and wooziness ghosted over the back of his head with a cold touch, but he shook it off.

'You look like shit,' Will said when he came into ear shot.

'What the hell happened?'

'I should be asking you that. What happened to you in there? You weren't having a seizure but you didn't respond for a good six minutes. CO19 had to get those bastards arrested and I have no idea how to deal with whatever happened to you. Is it PTSD from the shit that happened in summer?'

'I don't know. Drop it, okay? It was probably nothing. Tell me what happened after I was out.'

'You know what, Dred.'

'Don't call me that.'

'Sounds more badass than Leir,' he quipped with a smile that blew out with a sigh and winced when the paramedic fixed the bandage with a safety pin. 'It was someone in Trident I expect. Not the first time we've had a traitor.'

'The dealer, Katja?'

'Gone.'

'You've got a good idea of what she looks like?'

'Sure, but people can change that too easily. All you need is a good plastic surgeon and enough cash.'

Mordred groaned. 'Either we don't know where the weapons are coming in from, who has them, or when we do we can't get at them.'

'Marten's going to have a heavy load with the paperwork from this.'

Mordred hummed and glanced over the bystanders who were directed away from their little war-zone chunk of the street.

'The Met wasn't always this corrupt was it?' he asked and turned back to Will.

'Your guess is as good as mine. Not as if you're an innocent bunny either. Don't give me that look, Leir. I appreciate you even more cause of your murky past. It's not everyday you get brainwashed by a serial killing cult.'

Mordred's laugh burst out, abrupt, and made Will's grin grow, before his phone vibrated in his hand.

'Hang on a sec, Will,' he said and answered when he saw the caller. 'Update?'

'We've got a prime suspect,' Arthur replied.

'It's only Monday.'

'Time is life, Mordred. Amanda's sister says she'd been seeing a new man. She identified him as the guy in the photo and gave us an address, so we're moving to bring him in this afternoon for questioning. Warrant is being drawn up now. And the pathology report confirms C.O.D. as asphyxiation. She drowned in her own blood.'

Mordred sometimes hated working for the Met. He watched the CO19 start clearing out, higher ranking Intelligence officers climb into police cars as escorts for the remaining arrested, and more strangers watch with morbid curiosity from the sides.

'I should be there, in case he reacts badly. Text me the address.'

'Already did. Don't be late.'

'I'm leaving now,' Mordred said and hung up, catching Will's quirked eyebrow.

'Hot date?'

'Murder case.'

'As sexy as that is,' Will started and stepped towards him after thanking the medic. They were centimetres apart when he stopped, sleeve cut off to expose his muscle, the bandage, and general wear and tear. 'I doubt it's as dangerous as this gig. I hope you have a good time wishing you were back here with me.'

'Thanks, Will,' he said. 'And for the record, suggesting I'd be arranging a date after what just happened takes a special kind of-'

'Romantic disposition?'

Mordred smiled. 'Sure.'

'It's my curse,' Will told him with a shrug and wink. 'I'll check CCTV for Katja. Make sure you get some rest. See you tomorrow?'

'Yeah. Tomorrow.'

.

.

.

Arthur led them to the base of the stairs and stopped to check them all over. Alexander Denton, the boy in the picture and likely the last person to see Amanda alive if not the one who killed her, was in a flat two floors up. Magic would be involved and the thought terrified him. He kept a hand wrapped around his baton and took steady breaths.

'Mordred, you go in before me and only because you have magic. Gwaine, you and Percy take the rear. Leon, I want you to stay with the car in case he runs and contact Control for back up if you need it. Ready?'

Percy scoffed. 'Always.'

Gwaine looked down at his kevlar. 'Will these even help?'

'No,' Mordred said. 'He can kill you without a gun or a knife.'

'That's why you're here,' Leon chimed in.

Mordred gave him a smile. 'Just call me canon fodder.'

Leon eyed him. 'I prefer meat shield.'

Arthur watched them banter, how the hostility and camaraderie twisted together into something unfamiliar and ugly but perfectly natural, entirely familiar. Mordred had been a knight after all. He let the memory go quickly and got their attention with an, 'Oi, let's focus. Remember that Alexander might not have control over his magic.'

'That doesn't make me feel any better,' Percy muttered.

Gwaine nodded and looked up the stairwell. 'And how are we supposed to write a report on this? How did you even requisition the kit without CO19 taking your soul as a safety deposit?'

'The possible violent murderer part covered that. As for the report, Kilgharrah probably has a plan,' Arthur said then nodded to Mordred. The man looked ready, his mouth set and eyes dark. It struck something in Arthur's chest, the darkness in his eyes eerily close to that in Merlin's. He didn't know what it meant. He didn't want to know. 'Don't do anything stupid, all right?'

Mordred flashed a smirk but let it fall the next second. 'Nothing heroic on your end, then. If you have to get out then go. Don't wait or come back for me.'

'Wasn't planning to,' Gwaine said under his breath.

Arthur narrowed his eyes at the Irishman then leaned his stare into the only one with magic. It took a second to reign in his willpower, swallow his pride, and step aside. 'It won't come to that. I have to trust you. Lead the way, Mordred.'

The walk up was silent, just footsteps, breaths and the slight friction of kevlar against the tough fabric of uniform.

Mordred came up to the door and knocked with his fist. 'Alexander Denton, this is the Metropolitan Police. We need to talk to you about the murder of Amanda Matthews.'

They waited, Arthur beside the door frame with Percy and Gwaine blocking the hallway between them.

Mordred shared a look with Arthur when the silence continued then leaned into the door. 'We have a warrant to enter and search the premises.'

They gave it a few more seconds then Arthur watched as Mordred moved his hand down to the door's handle. In the quiet they heard the clicking of tumblers inside, saw the light flash in his eyes, then the door popped open an inch.

Mordred pushed it open further slowly, the glow in his eyes growing. Arthur kept close behind him as they stepped into the darkness. He had just passed the threshold when something shoved him to the right, out of the way of the door and it slammed shut. A shiver ran through his skin and he tried to open it again.

'Locked,' he whispered into the darkness, his team's voices muffled as they asked what was going on. Arthur sensed movement beside him when light flooded into the room, Mordred's finger on the switch next to the doorframe. It filled the air then flashed out again when the lightbulb whined loudly and glass exploded with sparks.

'I can't unlock the door, but at least,' Mordred told him quietly before he paused and a ribbon of white light coiled itself around his hand, held out in front of him, 'we can have some light.'

His hand was illuminated with an eerie soft glow. It coiled into his palm, merged its layers together to form a ball, then lifted up and pulsed out a stronger dome of white light. Arthur looked into the room, made out the obscure shape of a sofa, coffee table, existing like strange lumpy creatures in a forest at night. His heartbeat picked up with instinct, and he remembered the natural fear that came with being alone in the dark, the fear of monsters hiding in the shapes of tree trunks and branches when they camped in the woods.

Arthur moved forward, was instantly tugged back, and pulled behind Mordred who got out in front of him and held him there.

'You shouldn't be here,' a voice said, raspy and sourceless.

'Was it an accident, Alex?' Mordred asked softly. 'The power can be too much sometimes. I know. I really do. Don't make the situation worse. We can sort this out.'

'You have it too,' it said. It seemed like it came out from just beyond the white dome's threshold, from the condensed shadows that surrounded them. Arthur kept still as Mordred took the lead.

'I do.'

'I didn't want to do it.'

'I believe you, Alex.'

'It was just a second,' he continued. Arthur noticed the calmness, the low quality of it. He knew sadness, depression, in someone's voice. He'd heard the change in his own during the first weeks after the attack. 'I was angry for a second. One second and then I couldn't take it back. I couldn't undo it. I've never felt anything like it before. The power, the way I saw it in my head and then it actually happened. I just wish it hadn't been her. Is it like that for you?'

'Sometimes it is. Sometimes it's unbearable too,' Mordred said. He'd pulled him back far enough so that Arthur's face stared directly into the back of his head. 'Sometimes I wish it would all go away, but we have a gift, Alex. We need to use it carefully. Use it respectfully.'

'Respectfully? You're here to arrest me because I killed Amanda even though I loved her. Even though I didn't mean to.'

'No, we just want to talk-'

'You can't. I've got nothing now that she's gone, nothing except this feeling. This rush. It won't matter if you arrest me. You can't take it away.'

Mordred nudged him back a little. 'Arthur, get out.'

'Wha-'

'Now,' he repeated, the ball of light flickering as the air began to lick out against them, picking up speed with some strange wind force. 'Now!'

He gritted his teeth and turned around, tried the door again, began to ram his shoulder against the wood. Again, and again, and again. Percy was shouting through to him but Arthur couldn't make out what he was saying.

'Mordred!' he yelled back. The light was gone and he blinked against the unnatural dark. Mordred was gone. The wind rushed past his ears, howling and whispering in different pitches. His heart raced and then he heard a cracking noise, looking back to see the wood of the door splintering as if something were hacking away at it from the inside.

Arthur backed up and light burst back into the room. It was darker light. Redder. Fire chased itself along the back of the sofa, ran up the curtains, threw its red over the room with a terrifyingly lit gloom. He saw Mordred a few feet to the side and then a line of flame reached up between them in the splintered wood, a moving wall the wind beat into a wild frenzy. Oxygen and flames was a bad combination. Magical oxygen and fire was even worse.

'Mordred!' he shouted and jerked backwards when the wall lashed out at him. Arthur watched as Mordred moved his arms in a strange sequence, quelled part of the wall, but he stopped too soon and fell to his knees. 'Mordred!'

He had put his head to the ground, hands clutching fistfuls of his own hair, and cried out. The scream cut through the crackling rush like an animal's call at the dead of night. A cold wave swept through Arthur and his skin prickled. With his next breath he coughed, the smoke draining the air of light as it pooled on the ceiling above and sank lower. He embraced the rush of adrenaline and ran into the fire wall, jumped over as high as he could, cried out when heat sliced into his thigh, and hit the other side on his knees.

'Mordred?' he yelled, but the man was catatonic, eyes scrunched shut and muscles tensed. As he crawled over to him the floorboards fell out from beneath his palms and his back hit the ceiling, blackness burning his eyes and throat. Arthur fell back down onto the fire, rolled out of it, and started patting down the flames on his trousers, on the sleeves of his shirt. The heat throbbed against every part of his skin and bloomed in his chest and head with a painful ache.

He cleared his lungs with a gruesome sequence of coughs and yelled, 'Stop, Alex! You don't have to do this!'

The shape of a man stood over him the next second. His heart beat itself against his ribcage then Arthur noticed the flames burning up and out from his own left hand. The world around him grew fuzzy, inconsequential. The orange form licking up and out around his fingers wasn't possible. He watched it in horror, the fire, the incomprehensible pain. The next second it was gone and his hand was fine.

'Can you feel it?' a hot wet voice hissed into his right ear. 'The rush?'

Arthur struck out at the face next to his with a fist but Alex caught it and bent his fingers back with inhuman force. He cried out when the bones broke. The vice-like grip on his ruined hand disappeared with another rush of wind and Alex flew backwards, his body thrown through the window. An influx of oxygen drove the flames higher and hotter for a second.

The following quiet, the sudden calm of crackling heat and flames, none of it felt real. Another man stood a few feet ahead of him, materialised out of nothing, and Arthur's breath left him. The way he held himself, the tall silhouette, the presence.

'Mer-'

Mordred screamed and Arthur jerked his head to look at the man on his side, a trail of flames cutting across the carpet only a foot away from him. He limped over, saw his face covered in sweat, and tried not to shout at him when he said, 'Look at me, Mordred. Look at me. You're all right. You're all right, Mordred.'

His thick eyebrows, scrunched up to meet in the middle of his head smoothed out a little and he opened his eyes. Arthur's hand was on his shoulder and he squeezed it gently as he forced their bodies back away from the fire.

Mordred looked up at him.

People called out his name before the door crashed down, Gwaine and Percy both collapsing down with the momentum of it. Gwaine had a fire extinguisher in hand and started blasting the wet white foam over the room. It wasn't enough but it kept it at bay long enough to drag Mordred back out into the hallway. He grabbed his partly melted baton from the floor on the way and slid it back into his belt.

Arthur got up when Mordred nodded to him and headed to the hallway's window where streetlights had just turned on, their bulbs warming up and faint in the early evening gloom. He opened it and looked down. Alexander's body was below on the pavement, limbs splayed out like a biology experiment, face down and bloody. Leon had climbed out of the car, mouth leaned in to the radio. The reasonably busy street had come to an uncomfortable stop, filled with gasps and the few brave enough to get close to Alex's body in empty attempts to help. Others pointed up to where thick black smoke rolled up out of the broken window to his right. Leon waved them all back quickly and sternly.

'Get him out here,' Arthur ordered when he turned back into the hallway, slightly light-headed with adrenaline and frantic breaths. Smoke had spread out and drifted up to the ceiling. The fire alarm went off loud, painfully, and Arthur marched over to see Gwaine still spraying the extinguisher effortlessly inside the flat. Percy leaned down and helped Mordred up to his feet.

'Did Mordred do that?' Percy yelled, nodding to the window inside the flat, as he ensured the dazed man was secure in his grip.

'Haven't the foggiest,' he lied, coughed and wheezed out his next breath. Sirens wailed in the distance. 'You both need to leave.'

They obeyed and Arthur ducked under the smoke as much as he could.

'We can't contaminate the scene more than we have already, even if it'll all burn up anyway,' he shouted, grabbing Gwaine by the arm. 'We need to go.'

He dragged them out and shut the door, both panting hard. Gwaine's forehead was slick and dirty with smoke and he dropped the extinguisher with a low thud, barely audible over the alarm. They directed other residents outside as they left, making sure everybody was out of the building and on the dimming street.

The image of that man in the gloom stuck on his thoughts like tar. He'd saved them, somehow, but it couldn't be Merlin. Merlin was in a coma. Not quite dead but not entirely alive either.

Arthur breathed heavily once they were outside. Alexander's body was still there. Broken and bloody. He felt rooted to the spot, vaguely aware of the pain in his hand and leg, his lungs, but more focused on what he'd seen. It had happened so fast, just like when Merlin- When they were attacked. With the blood, the way it had kept coming, had covered his teeth and spilled out of his mouth. He'd been trying to cough it out, he hadn't been able to speak. Arthur winced when a branch of pain sprouted up his forearm.

'Hey,' Gwaine said next to him. 'Keep it together, mate.'

Arthur nodded and limped around the body towards Mordred who'd been sat down in the open passenger side of the car. The sirens grew louder.

'What did he do to you?' Arthur asked. When he didn't respond he added, 'You saved my life.'

Mordred wouldn't meet his eyes. 'No. I didn't.'

No, he hadn't. Arthur knew it but he couldn't acknowledge it. It didn't make sense.

'What do you mean?'

'It wasn't me,' he said and looked up. His frown deepened. 'Your hand.'

Arthur flipped his thoughts to stick with the sudden topic change. He looked at it, at the blood and the bruising. 'It's broken.'

Mordred reached out. 'Let me-'

'Don't.' Arthur stepped back. 'I've had enough magic for today.'

He looked back across the street to where Percy was laying a plastic sheet over the body. The ambulance rounded the corner and Gwaine walked up to wave it over just as a response van parked up by the scene, blue lights flashing across the buildings and bystanders, and seven or so uniforms poured out to help control the scene.

Arthur sighed. 'I swear to God this job will give me a heart attack one day. What the hell is going on?'

Mordred didn't respond. He looked down to see him lean forward and cradle his head in his hands. The fire engine arrived and Arthur leaned back against the car. His skin was sticky, hot and sore, with no chance of a shower or change of clothes for the next three hours minimum. Then would come forensics and then the statements. His head pounded. Every thought dripped through red and fragmented as Mordred's screams rang in his memory.

(Playlist for In the Dark:

-Ready by Kovas
-broken by lovelytheband
-NEW COKE by Health
-begin again (HEALTH remix) by Purity Ring
-Monsters by Ruelle
-Anachronism by Crywolf)