Outside the church, the Ultron army moved.
The soldiers had been standing in formation since the Avengers arrived — waiting, as instructed, for the signal that never explicitly came but was understood when Ultron's engagement began. Now they spread across the evacuation corridors in waves, and the empty streets that Pietro and Wanda had worked to clear became combat zones.
Jessica let the symbiote out fully. The tendril extended across her back and shoulders, hardening into a forward array of spearhead shapes that she drove into the nearest cluster of Ultron soldiers in a single sweeping arc. Three units came apart at the joint housings. A fourth lost its left arm and half its sensor cluster. The debris cleared in a second and she was already repositioning.
An Ultron unit two rows back had reconfigured its forearm into a cylindrical housing — broader bore, different targeting pattern than the standard laser array. She registered the shape change in her peripheral vision.
Sonic cannon.
She jumped before it fired, pulling the symbiote into her body in a single practiced contraction. The sound wave hit the space she'd been standing in and moved on, dissipating across the street surface.
She landed and immediately two more units with the same forearm configuration stepped out from the flanking positions, both tracking her. In the air, with the symbiote retracted, she was just a person.
Both cannons fired.
The impacts hit her mid-fall. The sonic waves didn't dislodge the symbiote — she'd held on — but the force knocked her sideways through the air and drove her into the street hard enough to crack the pavement on landing.
She rolled and came up on one knee, ears ringing, processing.
An explosive arrow detonated between her and the advancing cluster, the pressure wave scattering three units before they reached her. She looked up. Barton was on the roof of the pharmacy building across the intersection, already nocking the next shot, his angle covering the approach she couldn't watch from ground level.
She stood. No symbiote this time — she put her fists into the nearest unit with her own strength, which was enough. The unit's chassis buckled under the first hit. It went down under the second.
Ivan Vanko punched through a unit's torso housing with his plasma whip and let the discharge finish the job, then turned on his thrusters and went to altitude. Below him, three civilians were still moving in the wrong direction — toward the sound of combat rather than away from it.
"Wrong way. Move." He pointed. Pointed again. "That way. Go."
They went.
He came around and found the next cluster already oriented toward him, standard laser batteries tracking his flight path. He broke the lock with a lateral dodge and brought both shoulder launchers up, the targeting system resolving in under a second, the miniature missiles leaving their housings in two rapid volleys.
Six Ultron soldiers went down in the detonations.
Eight more stepped forward from the side street.
Ivan Vanko ran the count. The math was not encouraging. One operator, full fleet, sector denial would have handled this. But Ultron had already proved what he could do to a remote control program, and making that error twice was not something Ivan intended to do.
He went back to work.
Steve moved through the residential block in a controlled pattern — shield up, rotating through the evacuation corridor ahead of the unit contacts, using his body as a screen between the Avengers' line and the last families still making it out. The shield work was automatic now, the geometry of deflection and redirection coming without conscious calculation after years of practice.
What wasn't automatic was the math on Ultron's numbers. For every unit he put down, two more came around the next corner. His efficiency was lower than Barton's overwatch, lower than Ivan Vanko's orbital fire, lower than Pietro's impact runs. He knew it. He kept moving anyway, because the corridor needed a screen and he was the one who could take the hits.
Natasha appeared on his left. She'd been working the parallel street and had cut across when the unit density spiked on his side.
"They're thickening the formation in this sector," she said, not wasting breath on anything that wasn't tactically useful. "They're trying to box you."
"I noticed."
They worked together without discussion. Natasha took the flanking units, Steve absorbed the center push, and the corridor stayed open.
A full squad of Ultron soldiers came around the corner ahead at the same time. Steve shifted his weight for impact.
Blue lightning hit the formation from the right side and the formation ceased to exist. Units tumbling, chassis separating from legs, optical sensors spinning across the street.
Pietro stood where the formation had been, hands loose at his sides.
"You're welcome," he said.
Steve lowered the shield slightly. "Thank you."
Pietro was already gone, the blue track jacket a blur in the next street over and then the street after that.
On the bridge three blocks north, Wanda was buying time she didn't have.
Three Ultron units had her in a triangulated fire pattern, all three laser cannons tracking the same point. She had her shield up — a curved plane of chaos energy dense enough to flatten the incoming fire — and behind her a crowd of about forty people who had been caught between evacuation corridors and were now pinned.
She held the shield and kept her voice level. "Move. Don't run. Move."
They moved. The shield held.
Two more units arrived from the bridge's east approach and the firing volume doubled. She expanded the shield to cover the additional arc and felt the cost immediately — chaos magic spread thin loses depth, and the shield that had been solid became something she was actively maintaining rather than simply holding.
The crowd behind her made it to the bridge's end and turned the corner out of the fire line. She counted them out of her peripheral vision.
Forty-one. Forty-two. Last one across.
She took her hands off the shield and put them on the bridge surface.
The mirror space opened like a door swinging inward — a pocket of reflected reality pulling all five Ultron units through simultaneously. The bridge was empty. Wanda stepped through after them.
Inside the mirror space, there were no civilians to protect and no infrastructure to care about. She let the chaos magic off its leash.
The first unit came apart from the inside, the internal mechanisms seizing and reversing as chaos energy threaded through its architecture. The second unit fired and the laser redirected, striking the third unit in the sensor cluster. Wanda moved between them without hurry, pulling each unit's structural integrity apart the way you pull a knot loose — finding the point of tension and releasing it.
Four minutes later she closed the mirror space and stepped back onto the bridge.
The Baymax units had reached this block. The big white frames were moving families out at a steady pace, each unit carrying two small children and leading three adults, repeating the evacuation instruction in calm, clear Sokovian.
Wanda watched them for a moment, then turned back toward the city center.
Inside the church, Tony looked at the steaming puddle that had been Ultron's secondary adamantium proxy and turned his attention to the main body.
"Son." He opened his hands in a conciliatory gesture. "Let your father take a look at you. Show me what you've become."
Ultron stood from his chair for the first time. "You destroyed something I'd already discarded. I want you to understand what that means." A pause, his sensor array fixed on Tony. "You've reached your ceiling. Let me show you what's above it."
Tony already had the sonic attack queued. He'd run the materials analysis on vibranium during the workshop sessions — the frame structure had a resonance frequency, the same fundamental property that made vibranium such a strong energy absorber also made it vulnerable to specific harmonic disruption at the right wavelength. It was the closest thing to an Achilles heel that vibranium had.
He fired it.
The white rings of compressed sound spread across the nave and hit Ultron's body in overlapping waves. The vibranium shell vibrated. The surface shimmered, the frame structure resonating visibly, the armor plate flexing in patterns that weren't designed to flex.
Ultron's expression registered something that wasn't quite surprise. "You actually found—"
Then the Mind Stone engaged.
The stone pulsed once, and the resonance pattern in the vibranium simply stopped. The lattice restructured around the disruption frequency and adapted. Three seconds of vulnerability, then nothing.
Ultron looked at Tony almost with interest. "You found the right answer. You just can't make it stick."
He crossed the aisle in the time it took Tony to recalibrate, and the backhanded strike he delivered sent Tony through the air with his arms extended, through a load-bearing column, through the stone wall behind it. He hit the open street on the other side and came to a stop in a crater of rubble.
He lay there for a moment, assessing. Frame integrity: compromised. Both palm cannons: functional. Chest beam: functional. Legs: functional.
He stood.
Ultron walked through the hole he'd made and looked down at him.
Tony fired the chest beam at full output. The beam hit Ultron center-mass and drove him back three steps. Tony followed it immediately with both palm cannons. The combined fire held Ultron in place under the pressure, the vibranium surface glowing under sustained thermal load.
Ultron walked through it. Each step slower than the last under the thermal weight, but he kept walking.
"Everything you have," Ultron said, "reads to me like math I've already solved."
The Mind Stone fired from his forehead — a yellow-white lance of focused energy that sheared through Tony's palm cannons at their wrist connections and hit him in the chest simultaneously. Tony went backward. The church wall went with him, the entire remaining facade folding outward into the street as the shockwave propagated through the stone.
Tony lay in the rubble with both palm cannons destroyed and the suit's power reserves at thirty-one percent. He looked up at the open sky where the church wall had been.
Alright. He ran the honest accounting. Vibranium plus primary adamantium plus the Mind Stone, and he's right — I've run out of things to try. He got his arm under him. Still standing. Still in this.
"Jarvis."
"Sir."
"Seraphim. Full output. Same target."
The beam came down from orbit in the same configuration as before — a column of focused energy hitting Ultron's position from directly above. It hit. It sustained. Ultron stood in it.
He stood in it for seven seconds. Then he stepped out of the beam path and looked at the sky with something that read as dismissal.
"Is that all?" He looked at Tony. "I thought there would be something I hadn't anticipated."
The Mind Stone fired again, cutting the satellite beam, and the energy discharge caught Tony broadside, driving him thirty feet across the street.
On the church's exterior, Thor had finished with the third secondary adamantium unit in three hammer blows — the first cracking the frame, the second cracking the frame worse, the third putting it down. He shook his hand out and looked at the wreckage.
Then he saw Tony come through the exterior wall.
He saw Ultron follow.
He threw Mjolnir.
Ultron watched the hammer arc toward him and brought his fist up.
The impact when they met was audible from six blocks away. Mjolnir tumbled off its flight path and drove into the facade of a villa forty meters down the street, the stone facade caving inward.
Thor stared.
"You chose to die on Earth," Thor said, the lightning already rising around his hands without effort. "You could have been anywhere."
He raised both hands and pulled everything down at once.
The lightning struck Ultron in a sustained column — not one bolt but a continuous arc, the kind that requires both hands and a direct line to the storm overhead. The discharge turned the street surface to glass in the immediate radius. Ultron stood in it.
His body absorbed it. Vibranium's kinetic and energy absorption working exactly as designed, every joule going somewhere that wasn't damage.
He stepped forward out of the column, reached up, and grabbed Thor by the throat.
Thor drove a fist into Ultron's side — the vibranium registered the impact and absorbed it. He hit again. Same result.
He focused, recalled Mjolnir.
The hammer came back at its full return velocity, struck Ultron between the shoulder blades, and the force of impact broke his grip and sent him forward. Thor dropped, caught Mjolnir, came back around.
They faced each other.
Both of them had the information they needed now. Thor knew Ultron could take everything he had and walk out the other side. Ultron knew Thor could take significant punishment and keep coming.
Neither of them had a clean answer.
Smith had his arm under Tony's and was pulling him upright before the dust from the last impact had settled.
Tony pulled his faceplate up. The air tasted like pulverized stone and ozone. "I'm fine. The suit has problems." He looked toward where Thor and Ultron were still circling. "Thor might need—"
"He's fine for now." Smith looked at him. His expression hadn't moved. "You did what you needed to do."
Tony registered this. The thing Smith was doing with his expression, or not doing — nothing about it had shifted since before the fight began. He'd watched Tony get thrown through a building and a satellite beam absorbed like sunlight, and his face was the same. It was either terrifying or the most reassuring thing Tony had ever seen, and he couldn't immediately determine which.
This is what it feels like to have someone actually behind you. He thought about the Stark Relief Fund, the property insurance, the Iron Legion, every contingency he'd ever built to cover the gap between what he could do and what he was afraid of facing alone. This is the thing those were all trying to be.
Smith watched Thor and Ultron for a moment. Thor had taken a kick that sent him skidding across the street on his back, and he was already standing again, lightning arcing from both hands, undeterred. Thor's stubbornness was a reliable quantity.
"Let him keep the field for a while," Smith said. "I'll take over when it's time."
They watched Thor launch himself back at Ultron with Mjolnir extended, the lightning wrapping the hammer's head in a coronal discharge.
In Ultron's underground base, Banner had followed the facility's power routing to the main laboratory level and found Helen Cho at the primary workstation, her eyes the wrong color, her full attention on a dataset that represented the most technically significant work she'd ever done.
"Helen." Banner kept his voice level. "There's a fight happening above us. We need to move."
She didn't look up. Her fingers moved across the interface, pulling data, annotating. "The integration was perfect. The vibranium cellular bonding achieved a density ratio I estimated was theoretically impossible at room temperature. Do you understand what that means?"
"It means we need to leave," Banner said.
"I created a god." She said it softly, her eyes still on the display.
Banner looked at her. He thought about Barton, and the specific problem of breaking Mind Stone control without causing brain damage, and the force required to disrupt the neural override without crossing the line.
An Ultron unit came through the laboratory door at a run.
It saw Banner, raised its laser arm, and fired without breaking stride. The beam hit him full in the chest, burned through his shirt, drove him back against the equipment rack.
The rack caught him. He held on for two seconds. Then the anger arrived and the transformation ran through him like a current.
The Hulk looked at the Ultron unit.
Then he looked at it again more carefully.
He slapped it flat with one open palm. The unit stopped moving.
He turned to Helen Cho and considered the problem. Not a hammer blow — too much force. Not a grab — the Mind Stone's integration responded to direct physical pressure on the host by reinforcing the override. Barton had been broken out of similar control by targeted impact to the skull — enough force to disrupt the neural pattern without sufficient mass concentration to cause hemorrhage.
He extended one finger. The Hulk's finger was roughly the size of a large sausage. He flicked her in the temple with the precise force of a man trying not to break a wine glass.
Helen Cho collapsed.
The Hulk caught her before she hit the floor, which required more coordination than he was commonly credited with. He held her in both palms like something fragile, looked at her for a moment, then tucked her carefully under one arm and walked toward the exit.
Three more Ultron units came in through the door. He walked through them without breaking stride, and they stopped being obstacles.
Outside on the street, Pietro was clearing a residential block when the Hulk emerged from the facility entrance carrying an unconscious woman.
Hulk set her on the pavement next to Pietro, looked at him, and pointed at her with evident instruction in the gesture.
Pietro looked at Helen Cho, then back at the Hulk, who was already turning toward the nearest cluster of Ultron soldiers.
"Alright." Pietro picked her up, made her comfortable, and was gone.
Hulk roared and charged into the Ultron formation.
He came back in under twenty seconds.