Agent of Change

The last thing John Miller remembered was the sound of shattering glass and a blinding flash of light. He'd been driving home from his late shift, exhausted and barely paying attention, when the truck came barreling through the intersection. He didn't even have time to hit the brakes.

And then…nothing.

When he opened his eyes, he wasn't greeted by golden gates or flames—just a sterile white room filled with the low hum of fluorescent lights. The air smelled faintly of antiseptic, and his body felt oddly…light. No pain, no injuries, just a strange numbness.

"Agent Miller?"

The voice snapped him out of his daze. He turned his head toward the source, and there she was: Maria Hill, looking younger and sharper than he'd ever seen her on screen. Wait, on screen? The pieces began to click together in his mind, but they made no sense.

"I—uh, yeah?" he stammered, realizing too late that answering affirmatively to "Agent Miller" was probably a mistake.

Maria narrowed her eyes. "Director Fury wants a full report on your last assignment. Debriefing in ten."

She left the room without waiting for a response, leaving John to gape at the door. Fury? As in Nick Fury? He pinched his arm hard enough to leave a mark, but the situation didn't magically resolve itself.

He scrambled to his feet, taking in the tactical suit hanging on a nearby chair, the ID badge clipped to it that bore his face but not his name. The emblem on the card—S.H.I.E.L.D.—might as well have been a punch to the gut.

"No way," he whispered, staring at his reflection in the mirror across the room. His face was the same, but younger, sharper, and somehow more confident. The body beneath the crisp white shirt wasn't his doughy thirty-something frame either—it was lean, built, trained. The kind of physique you got from months in the field, not hours on the couch.

He rifled through the ID badge's details, his new name and rank staring back at him: Agent John Miller, Level 4.

That's when the date on the corner of the badge hit him like a freight train: April 2008.

"Oh, no. Oh, no, no, no."

He was in the MCU. Pre-Iron Man, pre-Avengers, pre-Thanos-snaps-half-the-universe MCU. It was the beginning of everything—and also, if he remembered the timeline correctly, the calm before one very long, very chaotic storm.

A knock at the door startled him.

"Agent Miller, you're late," came a gruff voice from the hall. John gulped and opened the door to find Phil Coulson, every bit the unassuming, no-nonsense agent he'd been in the films.

"Uh, right. On my way," John said, feigning professionalism while his brain spiraled into panic.

As he followed Coulson down the halls of what could only be the Triskelion, a new thought took root in his mind:

He wasn't just in the MCU—he was in S.H.I.E.L.D. And he wasn't a civilian bystander watching the chaos unfold. He was in the game, whether he wanted to be or not.

The question was, how much could he change without messing everything up?