How do I express sarcasm in non-dialogue text when writing a fiction novel?

“Ordinarily I would say yes, but as the Adversary continues to gain ground in this space, I find myself increasingly constrained. I fear you will need to make your own way.”

“What do you need me to do?” May said.

“Ah, forgive me once again. May, I would consider it a personal favour if you might consider doing a small task for me.” Spencer’s voice carried a note of supercilious sarcasm. “You might not die.”

Why do people procrastinate and how can they stop?

A moment later, the barrage ended. The dome, now considerably smaller than it had been, faded from view. That sense of presence returned to the statue. “I’m terribly sorry.” Spencer’s voice sounded thinner, somehow, weaker in May’s ears. “This situation is an intolerable nuisance. May, I wonder if we might impose on you to help save Serene’s life and ensure the future of the Guild? I wish I could say you’ll be fine, but I’m afraid the odds are rather good that you’ll die.”

“If you must know,” Spencer said in a tone that suggested she didn’t, “it will allow Serene to see through your eyes and utilise you as a conduit for her spellcasting abilities. If you please.”

“I’m a cat.”

Why do Trump supporters believe Trump should deport the immigrants? These people you call "illegal immigrants" have lived here for many years, they have houses, jobs, how can you think they will just go back to their country, where they have nothing?

“Good luck.” Serene stood. They embraced for a moment, then the air sizzled, the diagram flared, and May found herself standing, shuddering and queasy, at the foot of the skyscraper. She set out down the street in the strange twilit gloom of Spencer’s imaginary London, toward the scribble of the Thames and the sinister whirligig of the London Eye.

May stared down at her mug, half-expecting to see some strange brew of raw magical essence. Ordinary tea filled an ordinary china cup. She took a deep breath, then swallowed the liquid. Nothing in particular happened. “Thank you,” Spencer said. “Now, off you go.”

Serene’s face hardened. “I see. In any event, as long as he remains connected to it, I cannot escape. You need to break his connection.”

How can Democrats not feel hypocritical when they urge Trump not to be vengeful should be become president when the Democrats are trying to put Trump into prison?

May jumped. “Don’t sneak up on a girl like that! You almost scared me out of my skin.”

“Okay, okay, you don’t have to rub it in.” May ran a hand through her hair. “What do I need to do?”

“I didn’t realise you were so sarcastic.”

Why does my crush make me jealous about having a girlfriend?

“May,” Serene said, “I can’t—”

“What other things?”

In our upcoming novel London Under Veil, Eunice and I have a character who’s quite sarcastic:

We now told, by Senator Grassley, that on the FBI form about the Biden bribery story, there is a Burisma exec who says he has 17 tapes of his deal with the Biden. 15 of Hunter and 2 of Joe Biden? What would this do to Hunter/Joe Biden if released?

“But I can,” May said. “You helped me out when I was in a bind, and you didn’t even know me. Besides, Spencer’s right.”

“So hey, about that.” May followed the street along the bank of the river. Strange blurred figures walked along the sidewalk with her, looming threateningly over her, dim and amorphous save for their hands and legs. She shivered as she made her way around them. In the street, suggestions of cars screamed by, much too fast, as vague and indistinct as the walking figures except for the noise and stench they left in their wake. “That night you followed me home from the club…”

Sarcasm is, almost by definition, dialogue. In fact, Merriam-Webster defines it as:

Why in my 60s do I have a strong desire to suck cock and swallow?

“What?”

“Did you know they would try to grab me?”

“Right. Okay. Focus.” She hurried along, trotting through the London that was not London, surrounded by phantasmagorical impressions of people that flitted around her in silence. “So how does this work? Is this, like, a real-time simulation? Are those weird blurs actually people in the real London right now? If someone were walking down this street in real London, would they see people where I see those—whatever they are?”

How do you cope when your mother doesn't love you?

“Good heavens.” Annoyance touched Spencer’s voice. “We can’t be expected to figure out everything! You’ll have to work that bit out. Please, drink your tea.”

I’m not really sure how you’d convey sarcasm without dialogue, since sarcasm is, by its nature, intrinsically wedded to dialogue. It’s a form of expression.

So I’m not sure that you can have “sarcasm in non-dialogue text,” as sarcasm is generally defined in terms of something you say or express…or perhaps I’m just not getting what you’re trying to ask.

Do guys ever want to suck a dick even though they are straight?

“I’m still not entirely clear on what you want me to do.”

“The Adversary has placed sentries of a sort,” Spencer’s voice announced, “which I expect will grow more numerous as you get closer.”

“There are currently some…complications. The Adversary has created a significant intrusion into this space, territory they control. Their presence is, and I do not say this lightly, quite painful. I have done the best I can.”

How could Trump, with his deplorable garbage supporters, manage to win an election?

“I hardly think this is the time for a lesson on the mathematics of planar resonance in advanced multidimensional thaumaturgy.”

“Your objection is noted,” Spencer said. “If we may move on to the important bit of this conversation, I would be appreciative if you might make your way over to the Eye and see if you might sabotage or otherwise distract our opponents long enough for Serene to shake off this bothersome spell that’s trying to eat its way into her mind. I would do it myself, but as you can see, I’m a bit busy maintaining this place and limiting the Adversary’s access, though I will confess to some consternation at the effectiveness with which they’ve made their way in. It must be convenient to have access to a source of energy more powerful than anything ever recorded in the history of magic. Crude, our opponents, but highly effective. Anything can be weaponized if you put enough force behind it.”

“I cannot see the future.” A hint of impatience coloured Spencer’s voice. “At the moment, I think the task at hand is rather more pressing than the past.”

8 signs you're mentally stronger than 95% of people, according to psychology - VegOut

“Yes?”

a sharp and often satirical or ironic utterance designed to cut or give pain.

“I am, as I believe we have established already, a cat.”

Why is watching a man and a woman have sex considered perverted? It's how we all got here, it's what we do, I say if you want to watch porn then carry on!

I’m…hmm. I’ve seen this question float through my feed a couple of times now, and I’m still not quite sure I understand what you’re asking.

Serene raised her hand. “I don’t think this is a good—”

“Think of something. Make it good, or all is lost.”

Why do almost all the girls on Quora look beautiful?

“Lord Dormer is personally overseeing this attack on my mind,” Serene said. “He appears to be directly coupled to the accumulator. I do not know why he is not using more of the stored power within it.”

“You see?” Spencer’s voice came. “My logic is beyond reproach. Iris is too important to the future of the Guild to risk. Dia and Janet likewise. The other students lack May’s outside perspective, so they are less likely to succeed. May is the right choice: expendable, but still just capable enough to make victory possible.”

“Fine.” May rose from the small table. “The hard way it is.”

Have you ever dealt with a Christian narcissist?

“So sorry to disturb you,” Spencer said. “I thought you’d want to be informed of potential threats ahead. If I’ve misjudged, please don’t hesitate to let me know.”

“You could at least try to sugar-coat it a bit,” May grumbled.

Cambridge Dictionary concurs:

“No.”

“I can answer that,” May said. “They’ve already used most of that energy for something else. We still don’t understand exactly what. A directed spell of some sort, focused through a human sacrifice.”

“The Eye.”

“Can’t you just, like, blink me directly to where I need to be?” May said.

“In that case, lemme have it.”

“How?”

“Advanced what?” She picked up speed, finding as she raced along the sidewalk that her legs didn’t tire, her lungs didn’t burn. “Is that a thing?”

Spencer sighed, the sound coming from the air itself. “It’s not really tea, of course. It’s the tangible representation, within this space, of a spell. Specifically, a spell that will allow you to communicate with Serene from wherever you are, among other things.”

“Ah, of course. Listen, this is your space, or alternate reality, or dream, or whatever the hell it is, right? You’ve already zapped me around from place to place. Why am I hoofing it to wherever it is I’m going?”

the use of remarks that clearly mean the opposite of what they say, made in order to hurt someone's feelings or to criticize something in a humorous way

“Oh, I get it! You’re being snarky.”

“Right. The Eye. Why can’t you just teleport me there?”