Author's Notes: I got the medical details from Wikipedia and the 11th edition of Squire's Companion to the British Pharmacopoeia via GoogleBooks. No medical beta this time, so any mistakes are most definitely all mine!
"He's burning up. Billy, run and fetch a doctor. Mrs. Hudson, if you will assist me..."
Last winter it had seemed as if he could never get warm, that the cold of the mountains had seeped into his bones, but now the only cold is the runnel of fear that keeps his spine straight as he trudges through the oven that is Afghanistan in July. Thrice now he has made this journey from the baggage train to the battle, and this time he is carrying a half-filled waterbag over one shoulder as well as his medical kit. The bhistis are too frightened to do their work, and while he cannot blame them for being afraid, neither can he conceive of leaving the wounded he must tend without so much as a sip of water to comfort them. But water is heavy, he is learning, and even half-filled the bag slows his steps and makes him a better target for the bullets that stray past the lines of men and guns that are his goal. One sings past his ear, so close that he flinches from it as he would from a wasp, or a bee defending its hive, and stumbles. The dooley-bearers who have accompanied him fling themselves to the ground, dropping the dooley and yammering out high-pitched prayers, but he must not show his own fear. "Only a little farther," he tells them, comfortingly. "We shan't be long in finding someone to take back to the field hospital, I promise." It is a promise he knows he can keep. There are more wounded in this battle than he has ever seen. At least one of them will need to be carried. He sends his own prayer silently up to the sky, that none of these faithful brown men he has convinced to come with him will pay the price for his courage, and lest his own God is not listening, he adds a plea to their gods as well.
"What language is that, do you suppose?"
"I'm not sure it's only one. Some of the words seem to be Hindustani, but others I've never heard before. Pass me that washcloth. Once we cool him down he'll be more sensible."
Something is wrong. The lines of men which had been established to hold back the oncoming Afghans are beginning to crumble, and the men at the guns are hastily putting their horses into harness again. He finds the first downed man who might survive and orders the dooley bearers to take him back to the baggage, quick as they can, but stays to throw bandages over wounds and morphine injections into bared flesh before he too is caught up in the chaos of fleeing men. Although fleeing is far too strong a word. No one has the strength left to run. The native soldiers, thrown into battle without even breakfast to sustain them, are plodding blindly, and the European soldiers aren't much better. Someone pulls the water bag from his arm, and he is grateful until he realizes how much of the precious stuff is spilled onto the unforgiving ground. He follows the crowd, trying to help a boy whose leg has been opened by a bullet, and somehow comes up against a gaggle of wounded from the morning, thrown onto camels and mules and horses willy-nilly. His orderly, Murray, turns up, reeking of whiskey, and pushes a bottle at him. "It ain't much, sir, but it's wet." Wet and hot enough to put the cold of fear at bay, if only for a little. But he is careful not to drink too much. Other men, desperate for anything liquid, are not so careful, and they fall aside, despite the officers who exhort them to rise. The Afghans are coming. They won't be long delayed by looting what is left of the baggage. He cannot afford to get drunk.
"Just a little more. Yes, I know it tastes dreadful, but you must drink it. Blast it all, man, open your mouth!"
From somewhere he finds the resolve to do his best by the wounded. There are dozens in his care, and more being hauled along on gun carriages, and propped up by desperate comrades. His few supplies are soon depleted, not that there is much chance to stop and do a proper job. But anything can be a bandage if you wrap it tight enough, he tells himself, and tries not to think too much about heat exhaustion and dehydration and shock, all of which are taking a toll. He wishes he had the strength not to feel glad when the worst-off men go silent and still. He tells himself that he is merely tired, and wants less work, but the truth is that the groans of the dying rattle around inside his head until they are louder than the crack of Jezail rifles from the villages and pursuing troops, and he is desperate to know where the worst of the danger lies. Each corpse pulled from a saddle means another man can ride, and if the horses weren't as thirsty and exhausted as the men he would be tempted to climb on one and head for the distant hills. Surely a man alone would be less of a target than this wretched rabble! But he cannot leave, if for no other reason than Murray and the few dooley-bearers and assistants from the medical corps who still look to him for leadership. The sun will be going down soon in any case, and once it is night only a fool would try to ride fast over unknown terrain. "Stay close," he croaks at Murray. "I think they may try something once it gets dark."
"Turn up the gas, please, Mrs. Hudson, before you go. I cannot see my book."
"You should leave him rest a while, you know. And a few hours sleep in your own bed instead of that chair would do you no harm."
"Thank you all the same, but I don't think I can convince him to let go of my sleeve."
As the sun is at its most blinding, a swarm of Ghazis come out of the west, swinging swords and ululating like women at a wedding and shouting "Allahu Akbar". They've half a dozen men cut down before anyone can react, and then it seems like every soldier with a cartridge still in his rifle is firing. His own revolver is out, and he takes aim deliberately, sending three white-clad demons to the martyrdom they are seeking before the Ghazi charge dissipates. Murray is white to the lips, having barely escaped with his life, and has a cut on his arm, but the wound is not deep. He uses the last of the whiskey to disinfect it, and one of his own puttees to bind the arm. "Thank you, sir," Murray says as they start off again. "I'll do the same for you some other day." But it will not be some other day, for as they reach the top of a rise the crack of a Jezail rifle splits the twilight and something incredibly heavy slams into his shoulder. He falls to his knees and blinks at the gibbous moon, rising out of the east, wondering when the pain will begin.
"The chief symptoms of poisoning by the Datura stramonium are dilation of the pupil, increased heartrate, fever, hallucinations... yes, of course. It all matches. But how on earth did the poison get into you? And what is to be done about it?"
He remembers being on a horse; remembers Murray holding onto his leg to keep him from toppling off again as the horse lumbers through the pain-filled night. He wants it to be in the past, but every time he opens his eyes it is still true. Where is the sun? Has it hidden away somewhere, ashamed to show clear the miserable parade of cowards still plodding blindly toward Candahar? He is certain there is no more safety there than in any of the villages they have passed. They are not wanted here, and he would leave if he could. Would leave now, if only he were not still miserably afraid of dying. He clings to the saddlehorn with the hand that still works. Tries to nod when Murray asks him something, although he cannot comprehend the words. He closes his eyes again and tries not to think of water.
"I can't see how one of you might be poisoned and the other be free of any symptoms. If you have eaten the same foods..."
"Ah, but we haven't! I was sent a basket of fruit and a box of Turkish Delight by a grateful client. And as I have no fondness for Turkish Delight, I passed the box over to Watson."
"But if it was sent by a friend?"
"So the label said. But labels can be written by anyone. Billy! I need a telegram form!"
When the sun comes up at last they are still hours from the fort at Candahar, and with the sun comes back the heat of the Afghan desert. He is vaguely aware that he will sunburn without a shirt, but that mite of discomfort is nothing to the pain which has taken over his being. There is no part of him which does not hurt. Not his feet, trapped in his boots; not his hair, stiff with dried blood; not his gut, aching for something to fill in the hollows. But the shoulder is the worst, flaring with fresh agony each time he is jostled. He closes his jaw so tight his teeth hurt too, and only opens his eyes when he cannot bear to keep them closed for fear of not seeing a fresh attack from the Afghans. It is on one of these occasions that he realizes something has changed. The horse is stumbling forward to something that glimmers in the morning heat and he smells water for the first time in hours. He tries to tell Murray, but his tongue has swollen and his mouth is too dry for language. Hands are pulling him off of the horse, sending the pain into places his body did not know it could feel pain, and he is lain upon a grassy patch with other groaning men for a while, until someone comes to trickle thin mud into his mouth and tighten his bandages. But the water tastes like blood, and comes up again, in spasms that nearly choke him. He hears voices, hears the officers readying the march to continue. He does not want to move again; he dreads the pain that will come with every step. But more hands come, lifting him back into a saddle. He finds his voice then, as the fear of going on becomes too much to bear. "Oh, Mama!"
"It's nothing, Mr. Holmes. They all call for their mamas when they are this bad. And at least the emetic of copper sulphate has done its work. We've only to let the opium do the same."
"You're certain, Doctor?"
"As certain as may be. He ought to be watched, of course, but I can send round a nurse..."
"No, that won't be necessary."
He has fallen from the horse. He's lying in the swaying dark, listening to the sound of carbines and rifles in the distance. It is only after a very long time that he recognizes that he has somehow come to be lying in a dooley. It is put down, so that the bearers might change places with fresh men, and for a moment someone opens a flap of the cover to look in upon him. "Where?" he mouths, blinking against the sunlight that streams through the gap, and a strange voice assures him that they are nearly back to the fort and asks if he wants water. He nods, although he is almost too exhausted to swallow the few careful sips he is given. The flap is closed and the dooley is picked up again. It is hot and smells of dust and blood, but far less painful than clinging to the horse had been. Outside it there are men on horses who somehow have the energy to shout and cheer. There is a trumpet blaring and a drum being battered in a pattern he should know but cannot think to name. He cannot hold on to consciousness much longer, not now, even though he knows that he will never be safe again. As the pain and exhaustion take him under once more he wonders where Murray has got to.
"It was meant for both of us, of course, and we're lucky that you hadn't more than two pieces out of the box. Billy says you told him he could have the rest, but he was saving them to take home to his sisters. Thank goodness he hadn't the chance! Mrs. Hudson gave him half a crown to buy candy on his way home so I expect they'll still suffer, but not nearly so badly."
"As if you didn't give the boy a crown, and for the same reason! He told me as much as he danced out the door."
"Thank you, Mrs. Hudson. You can take the tray now."
"And you've eaten no more than he has, I see. You know what he'd tell you if he were awake."
"But he is not awake, and until he is..."
He reaches out a hand and catches a thin arm, opens his eyes to see wallpaper and a gas jet and two figures braced in familiar friendly combat. The woman is pink with pleasure. The man whose sleeve is under his hand is pale with inanition and lack of sleep, although the grey eyes have brightened now with pleased surprise. He has a part in this drama, he knows, but it is a long, confusing time before he can remember his words. "Holmes," he says, his voice cracking. "You need to eat."