Chapter Text
The tunnels were built to make people feel trapped.
Concrete walls pressed close on either side, reinforced with steel ribs every ten feet. The overhead lighting flickered in uneven patches, shadows pooling in places you could hide a dozen men. Somewhere behind them, the echo of gunfire rolled through the underground like distant thunder.
“Nat, Sam, status?” Steve’s voice was low but carried, his shield angled toward the dim stretch ahead.
“We’ve got the hostages,” Natasha replied over comms, the line sharp with background noise. “Moving to extraction point near the south entrance. Resistance is heavy near the surface but manageable.”
Sam cut in, breathing a little harder. “Manageable for you. They’re throwing everything they’ve got at us.”
Hill’s voice overrode them all, clipped and brisk. “Maintain positions. Rogers, Barton, Stark—you’re still on reactor duty. We need that thing down before it hits threshold. Then get out.”
Tony didn’t bother replying. He was too busy watching the schematic JARVIS was projecting on his HUD. The reactor room was close—one more curve in the tunnel. What caught his attention wasn’t the goal, though—it was the cluster of red markers half a klick behind them.
“Steve,” Tony said, tapping two fingers against the side of his helmet. “SHIELD’s front line’s about to collapse. Your agents are about to have a bad day.”
The markers weren’t surging forward. They were spacing themselves.
Tony didn’t like that.
Steve adjusted his stance, reading Tony’s tone. “Options?”
“One.” Tony angled his chin toward the suit’s projected route. “I send the armor back up-tunnel to clear debris and take pressure off your people. They push through, you reunite, everyone’s happy.”
“You’re without armor,” Clint said flatly. “Reactor’s still ahead. Not loving that math.”
“Reactor’s right there,” Tony countered. “Five minutes’ work, tops. You two can go play cavalry. I’ll meet you at the extraction point.”
“No,” Steve said immediately. “We don’t split here.”
Tony’s fingers moved anyway, unsealing the suit’s plating. “I’m needed in two places at once, so—” He didn’t finish. “J, route yourself to sector seven-five-alpha, priority override.”
The suit’s optics flickered in acknowledgment. “Confirmed, sir.”
Steve’s voice followed him down the tunnel. “Stark!”
Tony didnt stopped and didn’t turn all the way back either,“
Cap?”
“We’ll hold this line.” Steve’s eyes cut to Clint, who gave a short nod.
Tony’s mouth twitched into something that might have been approval. “Fine. Do your thing, Captain. I’ll do mine.”
The armor thundered away into the shadows, its glow vanishing around the bend. Only the right gauntlet remained, cool and solid around Tony’s forearm. It was something, for now.
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Cutaway – Natasha & Sam
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Natasha had one hand on the elbow of the nearest hostage, steering the group through a half-lit junction. The other hand kept her pistol ready, muzzle down but not relaxed. Sam trailed two paces behind, scanning their six.
“Almost to the service stairs,” Natasha murmured. “Hill, we’ll need a clear path topside.”
“Working it,” came Hill’s voice, brisk and distracted. “Multiple skirmishes between you and the exit. I’m diverting two teams—”
The line hissed with static, just for a second. Enough for Natasha’s eyes to narrow.
Up ahead, a heavy blast door stood half-open, its steel teeth sunk deep into the concrete. It had been like that when they came in—motionless, unpowered. Now, without warning, hydraulics shuddered to life.
“Move,” Natasha ordered, quickening her pace.
They didn’t make it. The door came down with a bone-deep slam, sealing the passage.
From behind them, another door slammed shut, trapping their small group in a narrow stretch of tunnel with three SHIELD agents, a half-dozen hostages… and four enemy guards who’d been running the opposite way.
Weapons came up on both sides, but Natasha’s voice cut the air like a blade. “Stand. Down.”
Sam’s eyes flicked to hers, reading the unspoken thought: This wasn’t random. Someone was locking the whole place down.
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Back to Reactor Room
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The reactor room was smaller than the schematics suggested — cramped, humming with residual heat. Tony dropped to one knee by the main access panel, gauntlet fingers already pulling the locking clamps apart.
Outside, the sound of fighting built steadily. Muffled thuds. Ricochet snaps against the tunnel walls. Steve barking orders in that battlefield voice.
Then Clint’s shout, sharp over comms and through the open door: “STARK, BREACH!”
Tony didn’t hesitate — he spun, raised the gauntlet, and sent two concussive blasts down the tunnel. The first wave of guards scattered. The second didn’t make it past the doorway before a wrist-mounted missile sent them sprawling.
“Go,” Tony said, locking the gauntlet’s flight command. “Clear the rest.”
The armor piece ripped free of his arm and shot toward the fight, leaving him horribly exposed.
He turned back to the panel and slammed the final override into place. Twenty seconds later, the reactor’s whine dropped to silence.
Tony flexed his now-bare right hand and gave the gauntlet recall command.
Nothing happened.
He frowned, tried again. Still nothing. HUD diagnostics stuttered, then blinked out entirely.
“Oh… shit.”
Steve and Clint stepped through the main doorway just in time, weapons still in hand. “We’re still not clear out there,” Clint said, eyes flicking back toward the tunnel. “Call the suit—”
Tony was already moving toward them, sharp urgency in his voice. “Out. Now. They’re locking it down—”
The blast door’s teeth slammed together with a metallic roar, missing Clint by inches as he jumped back. In the heartbeat before it sealed, he caught sight of other heavy doors down the corridor snapping shut in sequence, cutting off lines of sight one by one.
The noise outside—gunfire, shouting, boots pounding—was cut to nothing.
The silence that followed wasn’t relief. It was containment.
And then the other sound hit: the hiss of the inner maintenance door unlocking behind Tony.
He turned just in time to see half a dozen men in heavier armor step through. They moved like they belonged here, weapons already leveled.
From the front, boots pounded toward the doorway — Steve and Clint, pivoting back into the room — only to run straight into another wave of the same heavily armed squad.
The trap had closed from both sides.
“Too many,” Steve snapped, shifting his grip on the shield. “Don’t fight it.”
Clint’s jaw clenched, but he let his bow drop.
Tony’s hands curled into fists, every muscle screaming to do the opposite — but for now, he let the guards move in. His eyes stayed locked on the man in charge. Whoever wanted him this badly was about to be very, very sorry.
[Steve’s POV]
The inner door slammed shut behind Clint, the sound like a vault sealing. Steve heard the heavy locks slide home — thick steel, reinforced — and knew immediately there’d be no breaking through from either side.
They were trapped.
No Natasha. No Sam. No way out that didn’t go straight through the enemy.
Clint’s eyes flicked to Steve’s, reading the same calculation: they could take a few, but there were too many rifles in this room for even him to gamble. And Tony—unarmed, no armor—was standing a step back from the fight line, shoulders tense but hands already moving like he was still mid-calculation.
Steve had the sudden, uncomfortable thought that Stark had already writtenhimself out of the exit plan.
The second wave came fast. Black-armored guards fanned into position, methodical and efficient. Steve recognized the type: professional, disciplined, the kind who didn’t get rattled by a shouting Avenger.
One of them—a broad man with a scar that cut down into his beard—scanned them like inventory. His gaze lingered just a second longer on Tony.
“That one. Stark.”
A murmur from one of his men: “Suit’s still in corridor seven, took out the sentry gun.”
The lead guard smirked. “Makes it much easier. Taking him outta that thing sounded complicated.”
Steve’s fists clenched. “You don’t need to—”
The guard was already pulling out a small black case.
When he popped it open, Steve’s breath hitched.
The syringe inside was too large—thick, reinforced, not a sedative needle but a delivery system. As the light caught it, Steve saw the faint metallic glint suspended inside the barrel.
A chip.
V. V
Clint saw it too. His expression hardened instantly. “That’s not standard.”
“Yeah, no,” Tony said, backing up a step. “I’m good. I got all my shots. Flu, tetanus, and I even did the company wellness thing last month—so thanks, but no thanks.”
“Hold him,” the guard ordered.
Seven men moved at once.
Even cuffed, Tony Stark was a nightmare to pin down. He twisted, kicked, used every ounce of leverage his wiry frame could get against them. Steve would’ve called it reckless if he didn’t notice the rhythm—Tony was counting seconds.
“You really need this many guys for one non-super, non-spy guy?” Tony taunted, straining against the weight holding him to the floor. “I mean, what is this—buy-one-get-six-free?”
Clint, cuffed beside Steve, gave a low whistle. “He’s really making you work for it.”
Steve could see it now—the fight wasn’t just panic. Stark was buying time. Deliberately.
The lead guard crouched beside them, injector in hand. “Here’s a little something from the boss. Just for you.”
Steve’s voice went low, warning. “He’ll calm down. You don’t need that.”
The guard didn’t even glance at him.
Tony’s head snapped up, eyes locking on the syringe.
“Nope. Nope, nope, nope—don’t want it, don’t need it, you can absolutely regift that.” He twisted instinctively, trying to pull back. “Do I look like I need whatever that is? Because unless it’s an espresso IV, I’m not interested—”
“Hold him,” the guard said flatly.
Hands came down hard.
One guard planted a knee between Tony’s shoulders, forcing him face-down against the concrete. Another wrenched his cuffed wrists higher, locking his arms at an angle that stole what little leverage he had. A third braced his legs, pinning him completely.
Tony bucked once, sharp and furious. “Hey—hey, careful with the merchandise! This is a limited edition—”
A hand clamped around the back of his neck, fingers digging in, forcing his head to the side and baring the skin just below his ear. Tony sucked in a breath, teeth bared.
“Oh, come on,” he snapped, breath tight. “I’m already on the floor. This feels excessive—”
The humor cut off mid-word
The needle went in, biting hard into the side of his neck.
Tony jerked violently, a sharp curse tearing out of him mid-word as the world seemed to tilt. His body locked for a fraction of a second, muscles going rigid under the guards’ weight.
For half a second, his body went completely still—and Steve knew, with cold certainty, that whatever had just entered Tony Stark had been planned long before this moment.
Long before the doors closed