Remember, Remember, the fifth of November,
Gunpowder, treason and plot.
I see no reason why gunpowder treason
Should ever be forgot.
(Anon. 17th Century children's rhyme)

There was absolutely no getting away from it – John hated November 5th.

The run up to the traditional 'celebration' was bad enough, with irresponsible shop owners selling fireworks to under eighteens, and kids thinking it's funny to throw lit fireworks at unsuspecting passers-by. By the time the actual night of the 5th arrived John's nerves were frayed.

Be that as it may, nothing on earth would make him admit such weakness, and to date he had been very lucky in so much as he had been able to lose himself in inane television or mindless books – until tonight. Tonight Sherlock had received a call that had them chasing off across London.

xXx

"You didn't have to come." Sherlock was looking at him, narrow eyed, across the back seat of the taxi.

"What? What brought that on?" John stared back at him, his teeth clenched in grim determination.

"Well frankly John, you look like you'd rather be anywhere but here." There was a pause, then "I'd have thought you were just as ready for something to ease the boredom as I am, but here you are, looking…" His voice trailed off.

'Oh that's not good.' John thought to himself. Sherlock being lost for words can never be a good sign.

"I'm just tired, that's all." He bluffed. "I'd rather be at home in bed."

The younger man shook his head.

"No," he murmured. "That's not it." But his words were not particularly aimed at John, so the doctor held his peace and sat back, saying nothing.

By the time they reached the crime scene a multitude of firework parties were in full swing, and the sky was starting to fill with the multi-coloured sparkles and ear-splitting crackles of seasonal pyrotechnics.

Lestrade crossed to them as they climbed out of the vehicle.

"We need to work quickly on this." He said without preamble. "Our killer is still out there and still armed. It would seem he planned to cover the noise of this shooting with the sound of fireworks but for some reason he acted too early – either his hand was forced by the victim changing his routine, or he just lost it."

"Let's hope it's the former." John said fervently.

Lestrade nodded his agreement.

"The shooting happened just ten minutes before I called you – one of our officers" he gestured to a man in sweater and jeans standing a little way off. "Lives at the end of the street. He recognised the gunshot for what it was and called it in. I need you to have a look round the scene before we move in, see if you can work out where he's likely to have gone…"

Sherlock nodded, ducking under the crime scene tape.

John watched him walk away. He was about to relax his guard a little when he realised that Greg was looking at him with a concerned frown.

"You okay?"

"Just tired." He nodded, trying not to sound too tense. The night, combined with the constant effort to appear 'normal' was taking its toll. "I was hoping for an early night."

"Sorry mate!" Greg huffed out what could have been a laugh and slapped him on the shoulder. If he noticed that John jumped more than was necessary he didn't comment.

"John!" Sherlock's shout dragged his mind away from his worries, and he slipped under the barrier and crossed to his side. "John look at this."

The consulting detective pointed to a partial footprint almost hidden by fallen leaves.

"He went this way." And without a moment's thought the young man shot off like a bloodhound on a scent.

Torn between stopping to comply with Lestrade's shout and following his friend, John paused for just a second before jogging away from the crime scene.

xXx

The trail led them away from the residential areas and out onto Hampstead Heath. The expanse of common land with its clumps of trees and scrub bushes was dark, lit only by the flash of fireworks, and John felt his stomach clench in fear.

He was grateful for the fact that Sherlock was beside him, and the feel of the cold metal of his Sig was welcome against the small of his back – a steel security blanket.

Keeping sound to a minimum they made their way onto the heath, Sherlock trying to examine the area and find clues while John's eyes scanned the area, his Sig now nestling comfortably in his hand.

There was a sudden low whistling sound, and everything seemed to happen at once.

In the flash and flare of the firework a figure was illuminated off to the left of them, a tall man whose arm was swinging round towards them, the ominous shape of a gun in his hand.

John squeezed off a shot, putting a bullet into the man's forearm before he could complete his move, at almost the same time he pulled Sherlock down to crouch beside him as he stared, unblinking at the now injured criminal.

"Put your hands on your head and walk towards me – slowly!" John ordered.

Sherlock stared at him, as did the wounded man. Nobody moved.

Slowly, not lowering his gun John stood up.

"I said put your hands on your head and walk towards me slowly. Now move!"

Although neither man could understand what the ex-army captain was saying, the tone of his voice made his expectations clear.

Hurriedly, barely sparing a glance at his keyboard, Sherlock sent a text to Lestrade detailing their whereabouts, then he slipped his phone back into his pocket and taking great care not to startle his friend he too stood up.

"John? Do you want to give me the gun?"

Sherlock could see the tremors running through his friend's body, could hear the accelerated breathing and noted the sheen of sweat where the limited light touched his face.

John didn't take his eyes from the man in front of him.

Despite his injury the man held his arms out to the side in a gesture of surrender, but as he took a step forward another firework, sounding much like a low level missile shrieked across the common.

"Down!" John yelled, this time clearly in English. "Get down!" and he threw himself across Sherlock, twisting as he went, to bring his gun up and fire off another shot.

The murderer was lucky that John was moving awkwardly when he took the shot, and that he too had chosen that minute to run, for instead of entering his heart the bullet took him high in the shoulder, bringing him down to fall face first in the scrubby grass. He didn't move.

Easing himself out from under his friend Sherlock gently removed the gun from the other man's hand, and then crossed swiftly to where the injured perpetrator lay.

"You'll live." He said, quickly examining the downed man. "I suggest you don't try to move or I may find myself finishing what my friend over there started."

And with that he crossed back to where John was now sitting, his forearms crossed over his head as if to shield it from shrapnel or falling buildings.

Sherlock could hear his friend talking, his voice soft pleading, breaking now and then on a sob.

"Please, not again. Please, no, not this again. I can't lose anymore, please, let them live…"

Placing a soft hand on the doctor's shoulder Sherlock moved his arms from over his head with the other hand. John's eyes were wide and glassy, flicking from side to side, seeing horrors that Sherlock could only guess at.

Without stepping away he dialled the emergency services and requested an ambulance for a gunshot victim, then without hesitation made a second call to his brother.

"Sherlock," came the smooth Etonian tones. "To what do I owe this pleasure?"

"I need help for John." Sherlock replied without preamble. "He's in the throes of a PTSD attack, and has shot and wounded a criminal that we were chasing. I need him out of here fast."

"Where are you?"

Sherlock gave his brother the information, telling him to hurry before closing the call.

xXx

Blue lights and sirens heralded the arrival of both police and ambulance. Sherlock stayed close by John, shielding him from the stares of Lestrade's team.

"Is he hurt?" Greg stepped softly up beside them, frowning down at John's huddled and shaking form.

Sherlock shook his head and mouthed 'PTSD'. Greg's eyes widened with shock, then looked around at the fireworks lighting the sky.

"Do you want to get him over to my car?"

"No. Mycroft is sending a vehicle. When I move him I want to move him straight back home. I appreciate you will need to question him..."

"Forget that. It can wait – right now he needs to be away from here."

A nod of agreement was all the Detective Inspector received in response, but the look in Sherlock's eyes betrayed the depth of his gratitude.

The soft purr of an engine pulling to a halt just yards away galvanised Sherlock and Greg into action, and between then they got John to his feet and guided him to the anonymous looking black car.

The rear seat was empty – no Mycroft, no blank faced assistant playing on her Blackberry – and as soon as the two men were settled in the back the driver pulled away.

"Where are they going?" Sally spoke from behind Greg's shoulder as the pair of them watched the rear lights of the car disappearing into the distance.

"John's ill."

"Ill? Not injured?"

"No. I did wonder earlier if he was okay – he didn't look well." Greg said, remembering how John had looked at the crime scene.

"What about..."

"Not now Sally – I'll deal with it tomorrow. They won't be going anywhere." And silently Greg was praying that Mycroft would somehow get John official immunity from prosecution for shooting a suspect.

xXx

Mycroft was waiting in the flat when Sherlock and John arrived. He waited until his younger brother had guided his friend upstairs to his room and put him to bed before broaching the subject of what exactly had happened.

"Will John be alright up there on his own?" He asked.

"I've given him one of the sleeping tablets the army doctors prescribed for him. I know he doesn't like to take them – they've hardly been touched in the years that he's had them – but I think he needs to sleep through the rest of the night." Sherlock said as he returned to the living room.

"I know you would rather consign me to hell before you accept my help," Mycroft said placidly while nodding his agreement to his brother's assessment of John's needs. "But the truth is that John shot a suspect, and despite the fact that he was undoubtedly the killer the British judiciary frowns upon vigilante tactics."

Sherlock's eyes narrowed. Mycroft was right as much as he was loathe to admit it, John needed help in more ways than one.

"What do you propose?" He asked suspiciously.

"Not what you're thinking brother mine, that much is certain." Mycroft smiled. "I don't think sending him to a hospital psychiatric unit will be in the least bit helpful."

"No. This isn't something that can be cured."

"Precisely." He agreed with alacrity. "Putting strategies in place to prevent this happening again can wait until we have dealt with the immediate issues."

"And how do you propose we do that."

"I have arranged for the whole investigation to be taken into the hands of the security services."

An eloquent eyebrow rose at this. Mycroft smirked.

"Fortunately for us the original victim appears to be a former Foreign and Commonwealth Office employee, so my people are taking it over as it may have a possible diplomatic connection. John's part in this will be brought under our jurisdiction; we will conveniently 'lose' the identity of the operative involved." He picked up his umbrella from where he had left it propped up against the back of John's chair. "And Detective Inspector Lestrade's team will be 'advised' not to concern themselves with it."

Tension leaked out of Sherlock's shoulders as he realised that once again his brother had stepped up and come to their rescue.

"Thank you." He said softly.

"Don't mention it." Mycroft replied as he walked past him, yet as he reached the door he paused and looked back over his shoulder. "Do look after John won't you? He is deserving of your care and attention."

Any snarky remark that Sherlock might have made died on his lips. His brother was right. Grabbing his laptop he slowly made his way back to John's room, and made himself comfortable on the chair in the corner. If John woke in the night he intended to be there for him.

xXx

Awareness came back slowly. The vague sound of rapid tapping reached John's ears, and he screwed up his eyes, peering blearily into the early morning light.

"How are you feeling?"

John's head swivelled round to where Sherlock sat.

"Have you been there all night?"

"Yes, and you haven't answered my question." He cocked an eyebrow. "So?"

"Like shit." John replied with a grimace. "Did you fill my head with cotton wool for an experiment?"

A small laugh escaped the younger man.

"No, but I did give you a sleeping tablet. What do you remember of last night?"

Sitting up, John reached for the now stale glass of water on his bedside table and swallowed the warm liquid as if it was his first drink ever.

He scratched his head and rubbed his eyes, looking anywhere but at Sherlock. The other man recognised the delaying tactic, but didn't comment, waiting patiently until his friend was ready to speak.

"I thought we were... I was... back in Afghanistan. It sounded like I was caught in the middle of an ambush." Turning worried eyes on his flatmate he asked "Did I kill him?"

"No, fortunately despite the blood loss he will make a full recovery."

John blew out a breath, running a hand over his face.

"And that also accounts for the fact that neither he nor I could understand what you were saying."

"What?"

"You were shouting at him – orders I think, but the language..."

"Dari most likely." Pushing his hands through his hair John closed his eyes. "If I thought I was back in Kandahar I probably thought he was an insurgent. What about the police?"

"What about them?"

"Don't be obtuse Sherlock, we were on a case, the police will have known..."

"Taken care of John, Mycroft has it under control."

John was speechless. He knew how much his flatmate hated to call on his brother for help, but right at this moment he couldn't spare the energy to be anything other than thankful.

Sherlock rose and moved to the door.

"Come downstairs." He said "You need a cup of tea and breakfast."

"Are you making?"

Sherlock didn't deign to answer and John, after a moment of hesitation followed.

While Sherlock moved with ease around the kitchen, making tea for them both and toast for his friend, he explained what had happened from the minute the evening had gone – as he put it – 'pear shaped' until he had given John some medication and put him to bed, and then went on to explain Mycroft's method of intervention, and how there would be no case for him to answer for wounding the suspect.

By the time he had finished the doctor was staring sightlessly at the crumbs on his plate, a dull flush creeping across his cheeks.

"Christ!" he said finally, not raising his eyes to meet Sherlock's penetrating gaze. "I deserved to be locked up and the key thrown away."

"No!"

Startled, John looked up.

"Locking you up will serve no good purpose, otherwise my brother would have let them deal with you as part of the ongoing murder investigation, he'd have let you take your chances with the justice system."

John looked disbelieving.

Sherlock decided to let him think about that one, and instead asked the question that had been on his mind since they left Hampstead Heath.

"Why didn't you tell me?"

"I... I can't..." John shook his head and looked miserable.

"Yes you can John. Don't you realise this could have been avoided if only you had told me that Guy Fawkes night triggers your PTSD."

"But it shouldn't be like this..."

"No it shouldn't." Sherlock answered reasonably. "But it is, and trying to hide from it will not help matters. We need to find a way to deal with it."

"We?"

The younger man paused, trying to read in his friend's face the cause of the wariness he could see in his eyes. He drew in a deep breath.

"I'd like to help you."

"Why?"

"Because you need help to deal with this."

"I'm not a bloody charity case!" John snapped suddenly, his body language becoming defensive.

"No you're not," Sherlock stayed calm, keeping his voice and body relaxed. "But you are my friend. I want to help you because that's what friends do, isn't it?"

John stared for a moment, then visibly relaxed and offered his friend a tentative smile.

"Yes it is," he said finally, his voice soft. "Thank you."

Sherlock just nodded, and tilted his head towards the door and the sound of Mrs Hudson welcoming Lestrade.

"Lestrade will no doubt have already been briefed by Mycroft's minions, but he was concerned for you last night – you'll have to face him, or he'll just keep coming back."

At John's pained expression Sherlock grinned.

"Don't worry – if it gets too much I'll just be my usual obnoxious self and drive him away.

John looked at him, and for the first time since it all began smiled a wide, genuine smile.

"I'll hold you to that – now go and let him in before he breaks the door down."