The impact on the Moon was visible from Earth.
To the people looking up at the night sky, it appeared as if a second, smaller sun had ignited on the lunar surface. A flash of blinding white light, followed by the terrifying sight of the moon itself cracking. A fissure, bright and jagged, ran down the center of the satellite.
Inside the cavern, gravity had ceased to be a law and had become a suggestion.
Saitama's uppercut collided with God's hand. The "Cosmic Erase" energy—a purple wave of anti-existence—met the absolute physical force of the Serious Uppercut.
Reality screamed.
There was no sound, just pressure. The kind of pressure that turns coal into diamonds and diamonds into dust.
God's hand didn't break. It shattered like glass. The cosmic entity recoiled, stumbling back against the wall of the cavern, which crumbled into kilometers of debris.
Saitama landed back on a floating chunk of rock. His shirt was gone (obviously). His pants were tattered. One of his boots was missing.
"You're big," Saitama noted. "But you hit soft."
God narrowed its nebula-eyes.
Saitama didn't wait for the monologue. He leaped again.
He ping-ponged off the debris fields, a red-and-yellow blur. Consecutive Serious Side Hops. He created a thousand afterimages, surrounding the cosmic giant.
The afterimages vanished. But the real Saitama was already inside God's guard.
"Serious Headbutt."
Saitama rammed his chrome dome into God's chin.
The impact sent the giant flying upwards, smashing through the moon's crust and bursting out into space.
"He... he knocked God into orbit," Blue whispered from the floor of the cavern, nursing his broken ribs.
Genos dragged himself over to Blast, who was coughing up black ichor. "Blast! Are you functional?"
Blast wiped his mouth. "He broke the seal... Saitama actually broke it." He looked up through the hole in the ceiling where two gods were brawling. "But he made a mistake."
"Mistake?"
"God is strongest in the void," Blast grimaced, standing up shakily. "On the Moon, he was contained by the physical shell. Out there... he is infinite."
In space, God expanded. Unfettered by gravity or rock, he grew. He became the size of the Earth. A nebula in the shape of a man, spanning the horizon.
Saitama floated before him, a speck of dust against a hurricane.
Stars began to move. Not figuratively. God reached out and pulled constellations. He wove stars into a spear of pure plasma.
ORION'S LANCE.
He threw it.
A beam of stellar fire wider than Japan streaked toward Saitama.
Saitama put his hands on his hips. "That's shiny."
He took a breath (which he was holding again).
Serious Series: Serious Spit.
He spat. A single globule of saliva shot out at hypersonic speed. It hit the tip of the stellar lance.
The moisture hit the plasma. Physics got confused. The sheer kinetic energy of the spit destabilized the fusion reaction of the stars.
The lance exploded harmlessly miles away, scattering like fireworks.
Saitama floated closer. He pointed at Earth below them.
"You're too close to my house," Saitama transmitted by punching Morse code into the ether (don't ask).
"Move."
He cocked his fist back.
"Serious Series..."
Saitama focused. He wasn't thinking about rent. He wasn't thinking about dinner. For the first time in forever, he was thinking about the weight of his fist.
He remembered Genos's broken body. Fubuki's scars. The fear in King's eyes.
"Limit Breaker..."
SERIOUS PUNCH SQUARED.
This wasn't a technique he could do alone. He needed a wall to hit. He needed resistance.
God sensed the danger. For the first time, fear rippled through the cosmos. It raised all four arms (it grew two more just for this) to block.
Saitama punched.
The universe cracked. A spiderweb fracture appeared in the fabric of space-time.
The force hit God. The entity didn't fly back this time. It couldn't. The force was so great it pinned God against the fabric of reality itself.
God flattened. It became 2D. Then 1D. A line of light.
And then, with a sound like a television turning off—zap—God was punched through the crack in the universe.
Banished. Exiled to the space outside space.
Saitama floated there, fist still extended. Smoke rose from his knuckles.
The crack in reality healed itself slowly, stitching back together.
Saitama exhaled his breath. He looked at his hand. It was trembling slightly. Not from effort. From excitement.
"That," Saitama whispered in the silence of space. "Was a good punch."
Back on the Moon, the tremors stopped. The Keepers were dead. The monsters were dust.
Blast leaned against a fleshy wall. He smiled. "He did it. The crazy bald bastard actually did it."
The team gathered their wounded.
"Is it over?" Fubuki asked, looking at the starry sky.
"For now," Blast said. "He pushed him back into the Void. It will take him eons to crawl back."
Suddenly, a streak of yellow fire re-entered the cavern. Saitama landed, cratering the floor one last time.
He looked terrible. Bruised (a little). Burnt (a lot). Naked (mostly).
"Anyone have a spare towel?" Saitama asked.
Genos rushed forward, offering his own cape (which was somehow fireproof). "Sensei! Your vitals! Your power levels! You exceeded all known metrics!"
"Yeah, yeah," Saitama wrapped the cape around his waist like a skirt. "Where's the ship? I'm starving. Did Pig God eat the emergency snacks?"
Pig God looked away guiltily. "Maybe."
"DAMMIT!" Saitama yelled, his voice echoing in the cave. "That was the hardest fight of my life and I get no snacks?!"
Laughter bubbled up. First from Bang. Then Garou. Then Blue.
They laughed until they cried. They were alive. The moon was broken, the Earth was safe, and the strongest being in existence was throwing a tantrum over chips.
EPILOGUE: THE DAY AFTER
City Z was rebuilding (again).
The news cycle was insane. WHO BROKE THE MOON? was the headline on every channel. HERO ASSOCIATION DECLARES MOON 'MODERN ART' read another.
In a small, newly renovated apartment, Saitama sat at a table.
Fubuki was there, managing his schedule on a tablet. "Okay, so the UN wants to give you a medal. The Hero Association wants to give you a statue. And a fan club wants to give you... a lifetime supply of hair tonic?"
Saitama scowled. "Accept the tonic. Send it to Charcoal-san (Garou)."
Garou, who was currently arm-wrestling Genos in the corner (and winning), shouted, "I don't need hair tonic! My hair is perfect!"
"King!" Saitama yelled. "Are we ready?"
King sat on the floor, plugging in a new game console. "Just about. Mega-Smash Fighters 6. I unlocked the new character."
"Who is it?"
"Caped Baldy," King grinned. "His special move is 'Serious Table Flip'."
Saitama grabbed a controller. "Finally. A game I can win."
"Don't count on it," King said, selecting his character. "I play frame-perfect."
Blast stood on the balcony, watching them. He turned to Blue.
"I have to go back," Blast said quietly. "God is gone, but the seals need repairing."
"I know," Blue said. He didn't look angry anymore. Just resolved. "But visit. Okay? Don't be a ghost."
Blast smiled, putting a hand on his son's shoulder. "I will. Besides... I need to see if this bald guy ever learns to play video games properly."
Inside, the game started.
"Ready... FIGHT!"
Saitama mashed buttons frantically. "Punch! Punch! Why isn't he punching?!"
King calmly executed a 50-hit combo. "KO."
"UNFAIR!" Saitama threw the controller down. "This game is broken!"
"No, Sensei," Genos said, refilling Saitama's tea. "You just need to learn the inputs."
"I don't do inputs!" Saitama grumbled, crossing his arms. "I do punches!"
Fubuki laughed, a sound bright and clear in the warm room. "Maybe that's the one thing you can't punch, Saitama. A high score."
Saitama looked at his friends. At the food on the table. At the peaceful city outside.
He picked up the controller again.
"Double or nothing," he challenged King.
"You're on," King smiled.
And as the game started again, Saitama realized something.
His apartment was crowded. It was noisy. It was messy.
It was perfect.