They are tied together and hanging on a hook over, of all the asinine things, an acid bath.
A fucking acid bath.
It's not quite like it is in the movies. They never mention the vicious fumes in the movies, for one thing. Even suspended over it at this distance, the hydrogen chloride is doing ugly, violent things to the delicate tissues of John's nasal passages. Also, hanging from a hook is bloody uncomfortable. On every inhale, the enforced stretch shoots through him from his wrists to the small of his back.
Apparently Sherlock is feeling the burn, too. "The fumes might kill us before we ever make contact with the liquid," he observes, in the same tone he used this morning when he informed John he was taking the last of the lo mein.
It's a nice thought. Nasty as it is, death by inhalation is a lot friendlier than death by dissolving in fucking acid.
Sherlock's head lifts and tilts back, his hair a silky tug against John's. "I want you to know, John, I blame you for this."
John's jolt of surprise rocks them both. "Excuse me?" And whose idea was it to chase the homicidal maniac into a chemical plant? He snorts as rudely as he can manage with acid fumes curling up his nose. "This is rich. Sherlock sodding Holmes, the man of many archenemies, and the acid bath is somehow my fault."
"You and your spy movies!" Sherlock sneers. "The studios keep cranking out that pap so long as people like you continue to spoon it down. Thanks to you, we have bourgeois criminals cribbing them in their hackneyed attempts to impress me." He thrashes irritably in his bonds, incidentally thrashing John along with him. Scorn positively drips from his rich voice. "Death by Hollywood, John. I cannot think of a more degrading way to go."
The jostling hurts, with their weight wrenching at their arms and shoulders, and the tall gangly string bean at his back bends John in ways he's not meant to go besides. "Will you stop that," he hisses. "If I have to die, I'd at least like the dignity of having my arms still in their sockets."
At his back, Sherlock falls completely still. John grunts, their ropes tightening around him as his body takes on the extra burden of a 12 stone sack of intellectually advanced potatoes. "I'm sorry, John."
"It's okay, you didn't really hurt me." The words are idiotic and automatic, powered by John's sudden flare of alarm. He knows Sherlock means more than the jostling, but the defeat in that familiar voice is as unnatural as the resigned slump against John's back. John hadn't realized how constantly Sherlock was struggling till he stopped, and he doesn't want to acknowledge what that really means.
Some of the weight eases off him as Sherlock recovers a little from his slump, but he refuses to leave John to his denial. "I'm sorry. I can't get us out of this."
John heaves a sigh so deep it sets them swaying gently. "It's alright. You tried."
"John-"
"Sherlock." Bound back-to-back with their arms over their heads, John can't reach out to him. It strikes him, suddenly, that the last time he will ever see Sherlock's face was half an hour ago, in profile in the low blue light of the shipping and storage bay. And now Sherlock can't see John's face, either, to see that it really is alright. John executes a sort of undulating arch of his spine that's meant to stand in for what might be a reassuring hug, if they were face to face. "I'm glad I'm here. Together is better than apart."
They hang in silence for a moment, together and apart, immersed in their own thoughts. "John," Sherlock finally says in a frighteningly gentle tone.
"Yes?" John prepares himself instinctively. The tone of last confessions. He knows it well. For all the ones he's heard, though, this one is specifically for him. It sends a strange warm thrill through him.
"Under the circumstances, you should know that I love you."
There's another moment of silence; the sort that takes over at weddings and deathbeds. It's split by the crack of John's incredulous laughter.
It really fucking hurts to convulse with laughter while strung up on a hook.
Sherlock's head jerks towards him. "John?" He sounds caught between hurt and concern. John wants to reassure him, to explain, but he's too busy being winded. The laughter turns to wheezing turns to coughing for breath, and he has to spend a minute or so writhing in his ropes and hyperventilating on the stinging air before he can finally say what's filling his mind.
"You have the worst timing in the world." And just in case Sherlock somehow can't read John's answer in the fond exasperation lacing that statement, the follow-up lays it all out for him. "Why the hell couldn't you have told me that when we could do anything about it?"
But by then, of course, Sherlock isn't listening anymore. "John. Do that again."
"What?" Of course. Dying declarations of love. How boring. "Do what?"
"That thing with your hips. Do it again!"
It takes John a beat to realize Sherlock means the writhing, when John was trying to put his weight on the cords around their lower bodies so he could stop choking. Obediently, he starts moving, trying to deliberately recreate what he'd been doing out of reflex before. It feels a bit indecent, now that he's paying attention. But after a moment, he hears Sherlock laugh wickedly under his breath. That laugh. John tenses, because he knows it: Sherlock's gloating.
Sotto voce, the detective commands, "Keep it up, John. It loosens this knot just enough..."
John keeps squirming. They fall into a rhythm, John shifting in response to each tug on the cords. It's only a moment before their ropes begin to release them. "Grab the hook," Sherlock tells him.
And then they're crashing down on metal, scrambling to their feet, still winded, to dodge and flee from their angry captors.
The moment they can catch their breath, they begin laughing. "Today wasn't our day after all," Sherlock notes.
John laughs. "Wrong, you git." Grabbing Sherlock by the shirt, he pulls him down for a kiss. "It really was."