"Let's talk while we wait, John. You'll be able to track changes more easily, then."

"I'm…not sure what one tends to discuss under these circumstances."

"Perhaps," he hesitated, "perhaps this would be a good time to—"

"Are you mad?"

Sherlock paused again. He was running shaking fingertips over the edge of his bottom lip, staring into the lamplight.

"Not yet."

"Funny."

"What do people ever discuss?"

"The weather. Politics. Family."

"Dull."

"A bit of dullness is nice sometimes."

"Is it?"

"Sometimes." John had his toes curled up inside his boots and his left hand spasmed – telltale signs of the strain. Sherlock, he saw, noticed. His eyes were fixed on Sherlock, and he hated to blink, except that his eyes were burning. "It's all I want, now and then, you know? A few quiet days; months, even. A quiet, simple life, perhaps, some day. Convention does have its charms, Sherlock."

Holmes gave a long sigh, and Watson worried about him taking such deep breaths, so close to the burning lamp.

"I suppose it must, for some."

"How are you feeling?" John said, sitting forward in his seat and testing the air with shallow breaths.

"Not sure. It's a bit thick in here. Do you smell it?

"Uh-huh."

"Then, please, don't lean forward. Keep your head out of the smoke as much as you can. I don't like to think…" Holmes closed his eyes. "I want you safe."

"I can't see any smoke."

Sherlock's eyes snapped open. John saw that they were red. "But it's pouring off the top of the lamp. Are you certain you can't see it?"

"I'm sure."

"Must be the low light."

"Maybe you want to come nearer the window, too?"

"No, I'm fine." Sherlock ran his fingers through his curls and gave his head a subtle shake. "This case, though, John. This case! To think that you nearly threw that letter away!"

"It's been…I can hardly describe what it's been like. A lot to process."

"The smiling and beautiful countryside, hiding a heart of wickedness. Isn't that what I said? I should—" Holmes broke off into a sharp, shallow cough.

"What do you feel?"

His voice was rough. "Thirsty. My throat's burning a bit."

"Do you want a glass of water?"

"No, you'd have to come over here. Please, stay where you are. Though it would be good to have you closer, out of selfishness. I wish I could see you better, John. It would be a comfort. This, whatever this is, has me feeling suddenly very alone."

"Not much of a change then." Watson quipped, feeling afraid. Sherlock made no reply.

To John, the air was still perfectly clear, though it bore a stench that had his own head beginning to swim. He was deeply thankful for the on-shore breeze pushing in through the window. To think that, mere days ago, Sherlock had occupied that chair for long, lazy hours, while John had peacefully slept. Suddenly, Holmes was on his feet.

"Problem?"

"No," Sherlock replied, running his hands over his upper arms.

"Are you sure you want to carry on?"

"We must!" Sherlock spat, pounding the table and causing John and the lamp to jump, the powder to sift through its mesh. "Or how are we to win? But, finally, things are starting to be clear."

"Really? Good, that's—"

"We are indeed fighting an evil – didn't I say, John? – It's outside in the dark. I see him now. William was right."

John shifted in his chair. "Now, hang on. Just…what are you saying, Sherlock?"

"Don't turn to look."

"I'm not. There's nothing to see."

"Yes, there is."

"Sherlock, we've been here before. It's a drug, remember? You're starting to see things, just like you did in Devon, on the Baskerville case. It felt real then, too."

"I think I know the difference."

"Just…a friendly reminder."

"To hell with it, John! It isn't a drug. The lamp has nothing to do with the murders. John, I was wrong. Happy? There is no drug. The killer is there. He's real, and he's outside…this…house!"

"Stop it, now. Sherlock, you're starting to scare me."

"You should be scared! There's a killer standing at the door."

John rose and covered his nose and mouth with his sleeve. He moved towards the hall, but Sherlock was on him in a second, hauling him back into the room.

"Don't, Sherlock. You need out of here!"

"It's not finished."

"No, we know how this ends; we won't let it finish. Look, there's nothing at the door."

"There is!"

Sherlock, with adrenaline-fuelled strength, wrenched John around to face him. He held John's head in his hands, and John struggled to free himself.

"Stop it."

"If you turn, if you look, you'll be the one to die. I can't, John. I can't let you go."

"We have to get out, Sherlock!" John yelled, enunciating each word.

"It'll kill you!"

"No, you'll kill us."

"This is the only safe place left!"

"Come on, please, Sherlock! For me!"

"I won't…"

In that moment, Sherlock showed a new level of dread, and as it swept through him, his grip faltered, and John turned to the door. There was nothing there.

"NO!"

Suddenly, John felt Sherlock's arm around his throat as he pulled them both to the floor.

"You can't have him!" he shouted in the direction of the hall. Then to John, "Didn't I say? Why did you have to look?"

"Please. God."

"No. John! Stay…stay."

"We have to get out!"

"Don't leave me. Don't leave me alone. John, please, it would kill me. I need you. You're all that matters to me."

"This is senseless!"

"Haven't I always said?"

"Please."

"Haven't I… haven't I… John. Oh!" His voice was taken away by a body-wracking cough.

Sherlock slumped, awake still but with his strength suddenly sapped away as though it bled from him, and John heard his shoulders hit the floor with a heavy thud. He looked Sherlock in the face, and knew he had only seconds. John felt that he wasn't far behind, and used the little strength remaining in him to pull them both towards the open door. John saw the smoke now: it formed a tunnel, a horrific tunnel at the end of which was clear air, and freedom. The lower he kept them, the nearer the door they crawled, the lesser the fumes became.

John's heart was thrashing in his chest, his lungs screamed for relief, his skin felt on fire. Only the one, consuming goal of getting Holmes to safety left him in an ecstasy… Gas…GAS! Quick boys - an ecstasy of fumbling… John's mind was going to shreds on him. Under a sea-green light. Sea green eyes.

His limbs were crumbling to clay on the slates like black ice, but at long last they were out. John saw that Sherlock struggled to breathe, and he tore the neck of his shirt open as his last possible act. Spread bodily in the lane, they lay in a tangle of shaking, brittle limbs. Their chests heaved against the frigid dark, and they pulled the sweet air through their open, gasping mouths.

How long they lay there, John was never able to guess. He was aware of being unconscious for a time, though whether seconds or minutes…

He and Sherlock seemed to rise from the darkness of the poison together. John was the first on his knees, and he helped the taller man pull himself up, bracing him with a hand on each shoulder. It was Holmes who spoke first, his forehead against John's chest.

"That was possibly the stupidest thing I've ever done."

"Possibly?"

"I never should have put you in danger. I'm really, very sorry."

"Are you okay?"

"I'm sorry. I'm so very sorry. I never should have put you in harm's way."

"Where else would I be, if not here with you, Sherlock?"

Sherlock covered John's hands with his own, cold, for the first time John had known, and spent a few seconds in the simple act of breathing, before losing himself to an uncontrollable giggle, which John felt all the way through him.

"What?"

"Stupid idea, John, trying to drive us mad."

"Oh?"

"Oh, yes." Holmes said, raising his head at last and looking at him. "We're quite mad already."

Watson stood, drawing his hands over his face to wipe away the streaming tears. He gave a short, thick laugh.

"S-Speak for yourself."

"I never imagined the effects would be so strong."

"But, what happened to the others… to William, and-and…" John protested, helping Sherlock to lift himself to his feet.

"I genuinely thought I'd be able to cope."

"Idiot."

"Yes. We must give the room time to clear. Walk?"

"If you're up to it."

Sherlock began to descend the lane, walking as an old man might, stumbling once against a wall, and John stayed close by him.

"I think we can safely say that we've proven how this family met its end?"

"But who, who would do such an evil thing?"

They could hear the sea. Every window they passed was a blank socket in an empty skull. They were alone, and free.

"All the evidence points to Mortimer Tregennis as the killer in the first tragedy, even though he was the victim in the second one."

"Mortimer, really?"

"He told us, if you remember, that there had been some family problem, long since done with. I made something of that in my thoughts. How bitter had that division been? How cleanly could the wound have healed for a man exiled, by design or by choice, from his family home? Though we can't know for certain, I find it difficult to see Mortimer Tregennis as a forgiving man."

"No, I agree with you there, Sherlock. He had a cold sort of look, didn't he?"

"Yes, cold. Well put."

The lane evened out and spread into the harbour landing. In the dim clusters of lights that dotted the village and hills, John saw that the tide was out. The stony flats and the angled, grounded fishing boats were glazed with an oily slickness, illumined by the sweeping blue harbour light, regular as a slow heartbeat. Sherlock struck out across the stones and made for the whelk-littered, concrete walkway that joined the shore to the root of the far seawall against the rocks.

"Finally, if it wasn't him who threw the poisonous powder into the fire, then who? Only he could have approached that fire and not raised the suspicion of his siblings, and they never left their seats."

"So, that means…"

"Yes?"

"That means his own death was suicide."

"Not an impossible idea, John, on the face of it: his soul, heavy with guilt, couldn't bear the burden any longer, and all that rubbish."

"You don't think so?"

"No."

They walked in silence for a time, and John focussed on his footing. They took the uneven concrete slabs towards the sea wall: a distance that seemed half so long in the daylight but now stretched grandly before them.

When they reached the end, Holmes mounted the barnacled iron rungs of the ladder set into the concrete face of the sea wall and pulled himself onto the top, helping Watson when he followed suit.

"There are too many reasons against it and a whole corner of the puzzle which we've not set out."

"What, Sherlock?"

"John, if you write up this case for the blog, your readers will adore the twist about to unfold. And, if I'm not mistaken…" Holmes pointed one long finger to the end of the wall, where the rusting harbour beacon was bolted. In the popping-dark intervals between blue flashes, John saw a shadowy figure standing at the abrupt edge of the wall. Sherlock, projecting his full strength, strode out towards the end and John followed behind. The figure didn't move until they were only feet away.

"Good evening, Doctor Sterndale."

The figure gave no start of surprise. "Bit late to be out for a walk, Holmes."

"Mm. I'm afraid that we've been conducting an experiment in our sitting room that's left it unfit for purpose at the moment. As John can tell you, it's a regular habit of mine."

"You have some nerve, Holmes."

"Have I?"

"It's you that's chased me out here tonight. The whole village…"

"I wanted your help, Leon."

"I hate the idea of my private affairs being discussed… gossiped about. Can't a man have the privacy even to grieve? How dare you? You interfering…"

"I understand. The situation's a delicate one for you."

"Piss off."

"It would be a shame to have to bring it to the police."

"Is that a threat, Holmes?"

"A favour, for now."

"And why, dare I ask, do you suggest that I'd want favours from you?"

"Because, last night, you killed Mortimer Tregennis."

"What?" John interjected. Leon Sterndale, who had been standing on the edge of the concrete precipice, turned and advanced on Holmes.

"How dare you, sir! How dare you make such outrageous accusations against me!"

"Please, Leon."

"I have lived a long and difficult life, Holmes, in places where the only safety to be had was in keeping myself to myself because even the laws were against me."

"I know."

"It makes a man desperate, even dangerous."

"Leon…"

"But I was a good man, Holmes. I am—"

"Leon…"

"I don't want to hurt you!"

"And I have no wish to hurt you. Surely you can see that, Dr Sterndale?" Sherlock threw his arms wide. "Where are the police?"

Sterndale turned from Holmes and resumed his former place, his toes peeking over the crumbling edge of the wall. He stared, slump-shouldered, between his feet at the churning, black waters below, where John could just see, with each sweep of the beacon, sharp rocks gnashing in the foam.

"Leon, please!" Sherlock urged, afraid to move.

"Why did you come here tonight, Holmes?"

"To give you the chance to defend yourself."

"Defend myself?"

"I've just accused you of murder, Leon."

The man gave out a low, humourless laugh. "Thrusting in the dark, Holmes. But isn't that just your style?" he insinuated, twisting and turning a sharp eye on John. "You have no proof."

"I base my accusation on hard facts, Leon. Would you like to hear them?"

"Holmes, I have nothing to lose, now."

"You revealed your part in this the night you showed up on my doorstep."

"I never did!"

"You did so by coming back at all, Leon."

"I told you! I came back because—"

"Yes, I've heard your reasons," Sherlock interrupted. "A bit underwhelming, Doctor. Unconvincing, to say the least. Never mind them. You came to my door to find out what I was up to. I said nothing, and you assumed that you had to take things into your own hands, to soothe your own heartbreak."

John was feeling overwhelmed himself. He felt lost, no longer in step with his partner.

"How dare you," Sterndale growled.

"You left my door and went home, avoiding the main road so that you wouldn't be seen. Then you went straight to the vicarage, because you knew that time would be pressing. You pocketed a handful of gravel from the drover's track you took across the fields. It's an odd colour – reddish — most distinguishable against the chalkiness of the coastal soil. And you were wearing the same worn out plimsolls that's you're wearing right now. You passed through the vicar's back garden and you waited, unseen, for Mortimer to return. When he did, you stepped forward, stopping when you reached the spot below Mortimer's bedroom window. Then you threw the gravel at the window to catch his attention. The grit was all over the sill of that window this morning."

"You are the devil himself!"

"Thank you. It took only one handful to catch Mortimer's attention. He'd been on edge all day, after all. As well he might, having just destroyed his own family."

Leon was on the edge of losing control. "The coward!"

"You asked him to come down. He met you at the door, and he knew why you were there. But you were an old family friend; how could he refuse you without raising William's suspicions? He took you inside. You spoke together, during which time you checked to make sure the windows of the room were shut. Then you left, and stood watching through the window while Mortimer died. It takes a strong motive to move a man of your past to such violence."

Leon reached into his coat pocket and for a moment, John was stricken by fear. Though John was expecting a gun, Leon pulled out a photograph.

"There is my motive. You won't find a stronger."

He handed the photo to Sherlock, who shared it with John. The photo was black and white, and in the impossible light under the beacon, it took several flashes for John to put the image together in his mind. He saw two young men: they were shirtless and bronze-skinned, and standing among trees at a water edge. One was clearly Leon Sterndale as a polished youth. He had is arms thrown about the shoulders of the other, who had a familiar face.

"Owen Tregennis," Holmes voiced.

"Mortimer's brother?" John echoed.

"For days, I've only heard Brenda's name. What a terrible loss. She was so young. So much sympathy for the dead. There are more ways besides killing to take a life, Holmes. My Owen is gone to me. Gone forever: the one thing—the one thing that truly mattered to me. Our secret, for so many, many years."

"Tell me, Leon. It's safe now."

"It must be hard for a city boy like you to understand. You're very young, Holmes. You don't remember what it was like… before. Especially in the country, and in some other countries, where revealing yourself meant death. It's hard, very hard to change your attitude after enough years have passed. You can't really believe that the world is capable of changing around you."

"But it has."

"Oh, it has. Lucky for you," he said with bitterness, and in a blue sweep, John saw again that Sterndale looked at him. John looked at his feet. "But, incredibly – I can't tell you how incredibly – the laws changed. I'm an old fashioned man, at heart. Owen and I were to be married in the summer. William knew. He was to officiate, at a small, a private family wedding. The vicar knew our secret for a long time. Years. He loved Owen like a brother, you see. That's why he phoned me… that's why I came back."

Sterndale hadn't moved from the edge of the precipice. He swayed with the memory of his losses and the horror of facing a future alone.

"Go on, Leon."

Sterndale took something that crinkled from his pocket and tossed it in Holmes' direction. Holmes picked up the packet, and passed it to Watson, who read the label.

"Radix pedis diaboli. Devil's Foot Root."

"Have you ever heard of such a thing, Doctor?"

"No."

"Not surprising. It's a rare thing. When fresh and whole, it looks like the foot of a goat, and its effects… the name is an appropriate one, for many reasons."

"You discovered it on one of your study trips to Africa."

"It's used as an ordeal poison by the medicine men of some tribes in West Africa. They keep it a tightly guarded secret. I don't want to admit what I had to trade with them to obtain this one specimen."

"A pity you did."

"That's the truest thing you've said."

"Go on, Dr Sterndale."

"I've told you my connection to the Tregennis family. For Owen's sake, I was friendly with his siblings, and his father when he was alive. There was a time, when I was young and naïve, when I was always thinking, you see, of that impossible, far-off day when we might be one family. They had their own troubles, which came and went. I never cared for Mortimer, much as I tried. He was a scheming man, a talker. I've never much trusted talkers," he said with disgust."But I was friendly to him."

"What happened?"

"One day, two weeks ago, he came to my cottage and I showed him some of the odd things I've collected in my travels. I told him," he paused, struggling, "I told him of this powder, and what it could do… bring a man's worst fears to bear down on him, and how madness or death would follow if the exposure lasted too long. I boasted of its rarity, and of how unknown it was to Western science. He asked me questions, about-about how long was needed for the effects to take hold. I answered him! How could I have known that he—?" Sterndale wavered, one foot slipping over the edge. He came down hard on his rump, while the sea surged on at the base of the long drop.

"Try to keep hold of yourself, doctor."

"You see, William's phone call was very useful to me. Not only did it tell me how my Owen went mad, but also who had done it, and who, of course, had been responsible for the break-in at my house just the week before, and what had been taken. Who else but Mortimer could it have been?"

"And you were the only man able to discover his crime," John posed. Holmes responded with pride.

"Excellent, John."

"He had to have thought I would be in the air before news could reach me. I so very nearly was! And for what reason was my Owen so cruelly ruined? For money? For spite?"

"It would seem so."

"For nothing, then! The man was a criminal of the worst kind, but what jury would be sold on so wild a story, so lacking in evidence? I have no trust…I thought justice would be impossible if left in the hands of the law. So what was to be his punishment? I have been a good man, Mr Holmes, but my soul demanded revenge. The rest you know."

"You gave Mortimer the same horror that Owen felt, before ending his life."

"I had a gun on him, to keep him quiet and in his chair. My God! How he died. But he suffered nothing that my Owen had not, while it still mattered. Perhaps, if you ever love as I've done, you'll know what a man can be driven to, what madness possesses him when his love is threatened, and taken away. No man living can hurt me more than I've been hurt already. Death itself has no fear for me."

"And that was your plan, tonight? To throw yourself on the rocks?"

"It would be…a relief, Holmes."

"A man can bury himself in life as easily as in death."

"What do you mean?"

"Go to Kenya, Dr Sterndale. Lose yourself, but do it in life. I'm not prepared to stop you. If you move towards that edge again, though, I will stop you. I will bring you to justice."

Leon stood, slowly, as though decades had piled on him in the ensuing minutes, and after an excruciating wait, he took a step backwards, away from the edge of the wall.

"You are a good man, Holmes, the best of men."

"Goodbye, Dr Sterndale. I hope we never meet again."

Leon Sterndale never spoke another word. He walked past them, a man of lead, and disappeared down the long walk, his retreating back shrinking in the sweeping blue light, until at last he was gone from their sight. In that same moment, Sherlock's legs gave out from under him, and he sank to his knees and leaned his back against the rusting iron pole of the beacon. John followed him down, his heart on fire. He could see nothing but white sparks against the black silhouette of Holmes against the midnight blue sky. He reached out blindly, clasped Sherlock's neck between his shaking hands, and pulled him into a desperate kiss. Sherlock pulled away with a sharp intake of breath.

"John? Is…is this the right time to talk about it?"

"No, Sherlock. Now isn't the time to talk."

John had imagined, on countless occasions, what this moment would be like and, living it, he realised how papery and insubstantial those imaginings had been. He hadn't the taste, the sound, the weight of what he was experiencing now. He hadn't the thrill of feeling the kiss returned, the urgency of Holmes' arms pulling him nearer. He buried his fingers in the curly hair at the base of his neck, felt grit from the road where he'd fallen after their senseless experiment that evening. Sherlock broke away for air and pressed his hot cheekbone to John's temple. John let his hands slide down to grip Holmes' collar.

"It's cold out here, John."

"Is it?"

"Dangerous.

"Do you think we can go back to the cottage?"

"It should have cleared well enough by now."

Sherlock rose to his feet and gathered John to him, pulled him into another gentle kiss.

"Sherlock, let's have more holidays," John suggested as he turned them to begin the walk back.

"Not Cornwall."

"Not Cornwall," John agreed, smiling for the first time in what felt like days.

They began the long walk down to the harbour flats, side by side, but as far apart as safety and the width of the wall allowed.

"Not that I needed this holiday."

"No."

"Since I wasn't on the edge of a mental breakdown."

"No, of course not."

"I'm glad you're finally starting to see the obvious, John."

"It's been rather a week, hasn't it?"

"Yes."

"Lots to process."

Sherlock paused on the top rung of the ladder. "It has indeed." John crouched in front of him, clasping his face again, again demanding a kiss, again receiving it from cold, gentle lips. When he pulled back, Sherlock continued. "I'm rather looking forward to going back to Baker Street, now. That is, if Mrs Hudson hasn't changed the locks in our absence."

Sherlock started down the steps and John followed.

"Oh, yes. Yes, that's a point. The ceiling…"

"I think I've done worse things. I'll call tomorrow morning, and find out whether or not we've been evicted."

THE END

Again, thank you to everyone who has been following and commenting on this story. Please take a moment to leave a comment. I'm mainly on here to experiment and find out what's working and what's not in my writing. You help me achieve that and you have my thanks.

If there's a story you'd like to see me write, I'm very open to suggestions, being at a loose end, now, as far as FF is concerned!

Thanks for coming along for a ride with me. Enjoy your day :)