The "Beyond" era of Amazing Spider-Man has seen Ben Reilly return as Spider-Man, but when it became clear his new employers were up to no good, Peter Parker's clone found himself without a number of key memories. Those can't be recovered, meaning Ben no longer remembers key lessons and experiences in Peter Parker's life (like Uncle Ben's whole "With Great Power..." mantra).
As you might imagine, that's left Ben a little unhinged, and in this finale, the former Scarlet Spider attempted to steal Peter's memories by any means necessary. Ultimately, he falls to his death and is consumed by a substance that rewrites matter and destroys it, thereby hiding Maxine Danger's crimes.
Ben's girlfriend, Janine Godbe, travels beneath Beyond's remains and finds his body before learning that the former Spider-Man survived. Resurrected by the goo dubbed "Quantum-Shifting Polymers in a Psycho-Reactive Medium," Ben still sees a void when he looks in the mirror and smashes that before fleeing. Those missing memories mean the clone is now his own man, but what does that make him?
It's then we learn this web-slinger has a new costume, identity, and powers as the mysterious Chasm...
As for Peter, he recovers from his injuries and agrees to move in with Mary Jane Watson. With that, a mysterious figure appears at the window and appears to take the web-slinger with him. Clearly, this cliffhanger is setting the stage for Zeb Wells' Amazing Spider-Man #1 next month; could this be the start of whatever it is the hero does that results in the entire Marvel Universe turning against him?
We'll have to wait and see, but there were plenty of shocking revelations in today's issue #93!