The warehouse in New York's underdistrict pulsed with the portal's blue glow, a tear in the fabric of Earth-731's 2030 dystopia. Peter Parker, Mad Spider, stood before it, his blood-red costume a jagged crown, his spider-powers—strength, agility, regeneration—straining against the pain from Oscorp's electroshock torture. His laughter, a Joker-like roar, echoed as he faced Spider-Man 2099, whose sleek suit and red visor marked him as a warrior from another world. "Nice threads, future boy!" Peter quipped, his Deadpool-like humor sharp. Gwen Stacy clung to his side, her blonde hair matted, her blue eyes fierce with love and fear. "What is this, Peter?" she whispered, her hand steadying him. The underworld watched, their loyalty teetering, as heroes like Daredevil closed in outside.
Flashback: At 15, Peter and Gwen shared a rooftop picnic, their last happy moment before Oscorp's vans came. "We'll always have this," she said, her smile a promise. That promise held them now, a tether in the multiverse's pull.
Spider-Man 2099, Miguel O'Hara, explained: "You're a canon event, Peter. A Spider-Man destined to fall, to break your world for a greater purpose." He described the Spider-Verse, a web of realities where Spiders fought a multiversal war against anomalies threatening existence. Peter's madness, his villainy, was scripted—a tragedy to spark rebellion on Earth-731. "Join us," Miguel urged. "Fight for balance, or your world collapses." Peter's grin was sharp. "Sounds like a blast! But I'm no hero." Gwen's voice cut through: "You're my hero."
The pain flared, dropping Peter. Gwen's ritual began, her touch soothing his burning nerves, their bond obsessive. "We decide our fate," she said, her love a shield. Flashback: At 20, Gwen hacked Oscorp's systems to ease Peter's torture, her heart breaking as he laughed through pain. Now, her resolve anchored him, her choice clear—she'd follow him anywhere, even into the unknown.
The underworld stirred, some fleeing as Daredevil's silhouette appeared outside. Miguel's portal hummed, its pull magnetic. Peter's madness whispered destruction, but Gwen's love held stronger. "We're not done," she said, her tablet sparking one last time, uploading their story to the city's screens—a final defiance. Peter laughed, raw. "Let's shake the multiverse, Gwenny." Miguel nodded, respect in his eyes. "You're a wildcard, Parker. That's why we need you."
As they prepared, Black Panther breached the warehouse, his claws gleaming. Peter swung Gwen away, his webbing a blur, his regeneration healing gashes. "Bad kitty!" he taunted, his violence restrained by Gwen's plea: "We're leaving, Peter!" They reached the portal, the underworld scattering, their legacy cemented on Earth-731.
Cliffhanger: Mad Spider and Gwen step toward the portal, Miguel leading. "Ready for the big leagues?" Peter laughs, his madness teetering, as Gwen's hand tightens, their fate uncertain.