The Scyllax units hit the submarines like guided munitions.
Each one drove itself into the hull with a collision that registered as a dull percussive thud through the water, and then the chainsaw swords started their work, cutting along the seam lines where the hull sections joined, finding the weak geometry of the construction and exploiting it methodically. Where the blades could not finish the job cleanly, the mechanical tentacles went in through the cuts and pulled, and the metal gave way in the way metal gives way when the forces applied to it exceed what it was designed to tolerate.
Seven submarines. None of them made it to deep water. The ones that lost structural integrity first went down in pieces, internal atmospheres compressing and then releasing catastrophically as the hull sections separated. The ones that held together longer simply ran out of time, their internal spaces filling with cold Pacific water while the Scyllax units maintained contact and kept working. The ocean floor several hundred metres below received them in sequence over the course of the next hour, each wreck settling into the sediment with a finality that the dark and the cold and the distance from any surface made permanent.
No Hydra personnel escaped from Hydra Island.
Five hours after the catalyst ignited, the fire had burned everything on the island surface that was capable of burning and had begun consuming itself. The blue flames receded in patches, leaving a landscape of scorched rock and ash and the structural skeletons of whatever the heat had not fully dissolved. The Thunderhawks, running fuel reserves down toward minimum, found the least hazardous landing zones at the island's edge, setting down on ground that was still hot enough to raise heat shimmer from the rain-wet ash layer.
Nolan stepped out of the cabin and his first footfall sank several centimetres into the surface, the ash fine and soft and still radiating warmth upward through the armour's soles. A small cloud of pale grey particles drifted up around his boot and hung in the wet air before the rain pulled them down. He looked at the island and kept moving.
The automatic reconnaissance drones were already out, dispersing across the surface in a grid pattern, methodical and fast. The rain was reaching the ground now that the worst of the thermal upwelling had died, and it came down steadily, darkening the ash and releasing steam where it touched anything still holding significant heat.
Half an hour of drone reconnaissance turned up what they were looking for: an underground base entrance, the reinforced metal door partially melted out of true, its frame warped and buckled by temperatures it had not been designed to survive. It had held anyway, which was the point of reinforced construction, but holding had not saved whatever was inside.
Nolan drew the Warscythe and cleared the door with three strokes, the decomposition field eating through the distorted metal cleanly. Tyberos went through the opening first, Terminator armour scraping the frame, and the Scyllax Guardian-automata and drone units followed in a steady stream behind him. Nolan stepped through after them.
The interior was dark and still hot. Emergency lighting had failed somewhere in the first hour of the firestorm, and what light existed came from the drone units' illumination arrays and the dull red glow of metal that had not yet fully cooled. Along the corridors and in the doorways of the rooms they passed, the elite Hydra soldiers who had made it underground lay where they had fallen, collapsed in the particular way of people who had run out of air. Their expressions were not peaceful. Nothing about the way they had died had been peaceful.
Nolan walked past them and kept moving.
The main underground square opened up around them twelve minutes after entry. It was large enough to park a substantial number of vehicles, and those vehicles were still there, Hydra armour and transport units that had never been deployed, their crews dead before they could reach them. Whatever tactical response Hydra had planned for a ground assault, the firestorm had made it entirely theoretical.
In the centre of the square, arranged in a loose cluster, stood the snake-shaped mechanical constructions.
They were silver-white and large, each one fifteen metres long and three metres at the shoulder, built along a serpentine design that gave them a kind of passive menace even standing still. The alien technology in their construction was visible in the proportions, in the materials, in the way the surface plating articulated differently from anything manufactured by human engineering. Nolan counted five of them, all motionless, all dark.
Above the head of the nearest one, kneeling on one knee with one arm extended upward as though reaching for something that had not arrived, was the Hive.
The alien body was a humanoid aggregate of worm-like components, the individual pieces fused into a larger coherent form that moved and acted as a single organism. Or had moved. The posture said everything: one knee down, one hand up, the gesture frozen partway through whatever the Hive had intended as its final act. The high temperature had reached it before the act could be completed.
David scanned it methodically, the blue light in his eye sockets deepening and pulsing as the analysis ran.
"It is dead, my lord," he said, turning to Nolan. "Its fundamental biology, despite the significant structural difference from human physiology, shares the same basic dependency on stable temperature and available oxygen. Carbon-based life. It could survive brief vacuum exposure, but the catalyst burned for too long and at too high a temperature. By the time it registered the threat clearly enough to act on it and attempted to direct the mechanical constructions toward an exit route, the opportunity had already closed."
Nolan looked at the frozen posture of the thing and nodded once. He had expected something like this, but the confirmation was still worth having.
"Dead?" Tony's voice carried the specific quality of someone whose mental model of the situation had just been revised without warning. He was staring at the Hive with his faceplate raised, expression caught somewhere between surprise and something he could not quite name. "We came all this way and it's just... dead. I thought there would be at least a dramatic confrontation. That's usually how these things go. Final boss, last stand, several rounds of escalating difficulty."
Thor glanced at him sideways. "Tony. You built the thing that killed it. You were there when we dropped three canisters of it onto this island. What were you expecting?"
Tony opened his mouth, and closed it again.
The Heart of the Furnace came up in Nolan's hand and fired a concentrated stream of plasma balls across the distance to the Hive's body and the nearest snake-construction in a single sustained pull of the trigger. The azure plasma consumed both in approximately four seconds, the alien matter evaporating cleanly without leaving anything identifiable.
He holstered the weapon and the others turned to look at him.
"Precaution," he said, without looking up. "Some things resurrect."
Nobody argued with this. It was not an unreasonable policy.
David moved off with the Ogryn guard contingent to begin a full sweep of the underground base, cataloguing whatever alien technology the Hive had brought to Hydra before its operations here were permanently closed. The snake-constructions alone represented significant research value. Nolan watched them go, then turned to Tony and Thor.
The remaining Hydra faction was the topic he had been turning over since the briefing in Latveria. Alexander Pierce held his position inside the North American network, senior enough in the United Nations structure that a direct decapitation operation would produce international complications that the Inquisition was not yet positioned to absorb cleanly. Beyond Pierce, Hydra's North American presence was deeply entangled with S.H.I.E.L.D., the two organisations woven together at enough points that separating them required information Nolan did not currently have and that Rogers was actively working to develop.
He laid out his thinking: a raid, Tyberos and the Astartes guards, targeted and fast.
Tony's response was careful and honest. The entanglement problem was real. Moving on Pierce directly, given his UN profile, would generate exactly the kind of international attention that would complicate everything they had built in Latveria and were building elsewhere. Rogers was making progress and would continue making progress. The joint operations with Thor were working, reducing Hydra's combat strength and geographic reach steadily. Pierce would be handled, but handled correctly, which meant handled when the conditions were right rather than immediately.
Nolan stood with his arms folded inside the power armour and listened to all of it.
He did not say what he was also thinking, which was that the S.H.I.E.L.D. problem did not end with Hydra. That the institution itself, its structure, its accumulated intelligence capacity, its global reach, represented a problem he intended to address eventually, by methods that would look different to how Tony and Thor currently conceptualised their relationship with Rogers and with the organisation. That was a conversation for another time, with better preparation behind it.
For now, Tony's commitment was sufficient: Pierce would be dealt with, quietly and thoroughly, and the remaining Hydra fighters would be worn down through the ongoing joint operations until there was nothing left worth targeting.
Nolan held Tony's gaze for a moment, reading the weight behind the promise, and then accepted it.
Hydra had spread itself across the world for decades, embedded in governments and corporations and intelligence agencies on every continent. By the time the Thunderhawks lifted off the cooling ash of Hydra Island and turned back toward the horizon, that network was functionally gone. The European arm was rubble. The Pacific command structure was ash and settled wreckage on the ocean floor. The Antarctic installation was under new management. The Supreme Council was dead, three of the four by direct action and one by environmental consequence.
What remained in North America was a rearguard problem. Real, requiring attention, but a manageable scale compared to what had existed a week ago.
Nolan watched the island fall behind them through the rain-streaked viewport as the Thunderhawk climbed, the last of the blue-tinged smoke rising from it in thin columns that the storm wind bent sideways before dispersing entirely.
The war was not finished. But this part of it was.