The sonic boom arrived three seconds after Leon pierced the atmosphere.
At Mach 25, his descent scarred the night sky – a jagged lightning bolt of superheated plasma ripping through cloudbanks. Stratospheric ice crystals vaporized in his wake, forming a luminous contrail visible from Baghdad to Beijing.
He slowed with the grace of a meteorite deciding to park. Five thousand meters per second squared deceleration would liquefy human organs, but Leon's boot soles kissed Afghan sandstone gently as a dandelion seed.
The cave complex glowed in his vision like an ant colony under X-ray. Twenty meters of granite between him and Tony might as well have been rice paper.
Crunch.
Leon landed in a three-point stance straight out of a Marvel movie poster, knee-deep in pulverized bedrock. Rubble cascaded around him in slow motion, each pebble deflected by an invisible bioelectric field.
Tony Stark awoke to Armageddon.
"Goddamn camel spiders evolved nukes now?!" The genius billionaire scrambled backward, sheets tangling around his legs. His eyes adjusted to the dust-choked air, locking onto the silhouette haloed by moonlight streaming through the fresh skylight.
"Delivery for Anthony Edward Stark." Leon straightened, brushing limestone powder from his cargo pants. "Next-day shipping from low Earth orbit."
Tony's mouth worked soundlessly. His hands flew to the arc reactor glowing in his chest – a primal gesture, like clutching rosary beads. "This... this is hypoxia-induced hallucination. Must've botched the palladium filter again..."
"Still using that potato battery?" Leon flicked the reactor casing with a fingernail. The ping echoed through the cavern. "Tsk. Even Hammer Industries' knockoffs have better aesthetics."
Reality crashed over Tony. He seized Leon's forearm – solid, warm, real – and promptly pinched himself. "Ow! Okay, not dreaming. Then how in Thanos' purple ass are you here? Your solar spa appointment wasn't..."
"Cutting it short." Leon's gaze swept the cave. Crude missile schematics covered the walls, intermixed with equations Tony had scribbled during feverish nights. "Heard my big brother needed a pick-me-up."
Tony's laughter came out shaky. "You interstellar stalker. Since when do you..." His voice cracked. All the bravado drained away, leaving raw exhaustion. "Christ, kid. You shouldn't be here."
Leon crouched eye-level with the man who'd raised him. Up close, Tony's genius looked fragile – beard overgrown, tremor in the hands that built empires. The Mark I armor stood half-assembled in shadows, its welds jagged as scar tissue.
"Wrong." Leon snapped his fingers.
The terrorists' armory three levels above detonated in a chain reaction of sparking circuits. Screams echoed through ventilation shafts, cut short by the whump of collapsing ceilings.
"Should've come sooner."