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The first time Peggy notices it, it is raining, not dramatically, not poetically, but with the sort of cold, soaking persistence that seeps into boots and morale alike. The farmhouse they’ve requisitioned sits hunched against the grey Ardennes sky, its windows fogged, its walls lined with maps that curl at the edges no matter how often Peggy flattens them. Steve is supposed to be studying one of those maps. Instead, he is watching her like she is the only thing in the room not slowly dissolving under the weight of the war.
She can feel it before she sees it. The attention. The way his gaze lingers too long, soft but unwavering, as if he’s memorizing her in case the world decides to take her away next. Peggy keeps her eyes on her paperwork for a full thirty seconds longer than necessary, just to see if he’ll stop.
He doesn’t.
“Captain Rogers,” she says finally, crisp and precise, pencil never pausing in its movement. “If you continue staring at me like that, I’ll be forced to assume you’ve forgotten how to read a map.”
There’s a scuffle of movement. A chair leg scrapes. “Sorry—Peggy, I mean—Agent Carter. I wasn’t—“
She looks up then, deliberately, catching him mid-fluster. His ears are pink, his hair damp from patrol, his jacket abandoned over the back of a chair like he forgot it existed the second he stepped into the room. He looks exhausted. He looks earnest. He looks unfairly handsome in that quietly devastating way that has nothing to do with the serum and everything to do with the way he cares.
Peggy exhales, some of the sharpness leaving her shoulders. “Come here,” she says, softer now.
He obeys immediately. He always does.
Instead of the map, she slides a scrap of paper toward him, creased, unassuming, covered in a careful grid of letters and numbers. His brow furrows as he studies it.
“What’s this?” he asks.
“A cipher,” Peggy replies, matter-of-fact. “Vigenère. Simple enough to learn quickly, complex enough to keep prying eyes out. The SSR uses it for lower-level communications in the field.”
Steve looks up at her, something like hope flickering behind his confusion. “You think I can learn this?”
Peggy arches a brow. “I think you’re far more capable than you give yourself credit for. Now—key word is Brooklyn. Write it above the text. Line it up properly.”
His mouth quirks at the word, fond and a little stunned, but he does as told, painstakingly careful. She watches his hands as he works, the way he treats the paper like something fragile, something important. It’s absurd, really, how much affection that simple attention stirs in her.
“Now decode,” she says.
It takes him a moment. Then another. Letters fall into place. Words emerge.
Steve’s breath catches.
“Peggy,” he murmurs, voice dropping instinctively. “This says—“
“Yes,” she interrupts lightly, already turning back to her papers as though she hasn’t just detonated something between them. “It does.”
If you survive tonight, I’m kissing you somewhere inappropriate.
He stares at the sentence, then up at her, then back at the sentence again, as if it might change if he looks too closely. A quiet laugh escapes him, disbelieving, a little breathless.
“You can’t just—what if someone finds this?”
Peggy leans in closer, her shoulder brushing his arm, her voice pitched low and certain. “Then they’ll see nonsense. Static. Meaningless marks on a page.” She taps the paper once. “But to you, it’s perfectly clear.”
Steve swallows. Hard.
That night, as he prepares to leave, he finds another note tucked into the lining of his jacket. He decodes it by flashlight later, crouched behind a hedgerow while the rain soaks into his knees.
Try not to get shot. I’ve grown fond of you.
He presses the paper flat against his chest like a talisman and goes back out into the dark with a steadier heart.
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It becomes a rhythm.
Peggy slips coded notes into the small, overlooked spaces of his lifel folded into his helmet liner, tucked beneath his canteen, hidden between the pages of his notebook where he keeps lists of names he refuses to forget. Sometimes they’re practical, coordinates, reminders, warnings masked as innocuous strings of letters. Sometimes they’re unmistakably not.
You looked unfairly good today. I blame the uniform.
When this is over, I’m taking you dancing. This is not a request.
You follow instructions very well, Captain. I appreciate that about you.
Steve learns fast. Faster than anyone expects. He practices in the margins of his journal, mumuring keys under his breath, committing patterns to memory like they might save his life, because in some quiet, essential way, they do. When Peggy switches to a different cipher without warning, he catches it within minutes. When she tests him with a book cipher, he spends half an hour decoding it by candlelight and emerges red-faced and triumphant.
He starts writing back.
At first, his replies are careful, formal, as if he’s afraid the wrong phrasing might break the spell.
Cipher successful. Message received. You are… distracting.
Peggy laughs aloud when she reads that one, startling Barnes across the room.
Then they grow bolder.
I think about your voice when it’s quiet.
If I don’t come back, please know I wanted to kiss you since the first week.
She doesn’t sleep that night. She sits with her back against the wall, rereading the note until dawn stains the sky pale and exhausted.
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The mission that nearly breaks them comes without warning.
Steve returns hours later than expected, bruised and bleeding, uniform torn, eyes still sharp but too bright. Peggy patches him up with hands that are steadier than she feels, jaw locked tight against everything she refuses to say aloud. She tells him he’s reckless. She tells him he needs to be more careful. She does not tell him how close she came to imagining a world without him in it.
When she finishes, he reaches into his pocket and produces a folded scrap of paper, already smudged with dirt and blood.
“I figured,” he says quietly, “I’d use what you taught me.”
She takes it. Decodes it instantly.
I survived. I’d like my reward now.
Peggy looks up at him, her expression warring between fury and relief and something dangerously close to joy.
“Crikey O’Reilly, Rogers,” she murmurs. “You really are learning.”
She kisses him then, brief, fierce, and utterly unapologetic. Somewhere inappropriate. Somewhere earned. His hands hover for half a second before settling at her waist like he’s been waiting for permission all along.
Later, when the war drags on, and certainty remains a luxury neither of them can afford, they keep writing to each other in code. Because even under fire, even surrounded by chaos, Peggy Carter believes in privacy. In intention. In choosing love deliberately.
And Steve Rogers, decoding her words by lamplight, knows that some things, once learned, are impossible to forget.