PHILADELPHIA >> After 50 years of spinning webs and catching a who’s who of criminals, Peter Parker is out of the hero game.

But Spider-Man is still slinging from building to building — reborn, refreshed and revived with a new sense of the old maxim that Ben Parker taught his then-fledgling nephew that “with great power, comes great responsibility.”

Writer Dan Slott, who’s been penning Spidey adventures for the better part of the last 100 issues for Marvel Entertainment, said the culmination of the story is a new, dramatically different direction for the Steve Ditko and Stan Lee-created hero.

“This is an epic turn,” Slott said. “I’ve been writing Spider-Man for 70-plus issues. Every now and then, you have to shake it up. … The reason Spider-Man is one of the longest running characters is they always find a way to keep it fresh. Something to shake up the mix.”

And in the pages of issue 700, out Wednesday, it’s not just shaken up, it’s turned head over heels, spun in circles, kicked sky high and cracked wide open.

Parker’s mind is trapped in the withered, decaying dying body of his nemesis, Doctor Octopus aka Otto Octavius. Where’s Doc Ock? Inside Parker’s super-powered shell, learning what life is like for the brilliant researcher who happens to count the Avengers and Fantastic Four as friends and family.

The two clash mightily in the pages of issue 700, illustrated by Humberto Ramos and Victor Olazaba. But it’s Octavius who wins out and Parker is, at least for now, gone for good, but not before one more act of heroism.

Slott said that it’s Parker, whose memories envelop Octavius, who shows the villain what it means to be a hero.

“Gone are his days of villainy, but since it’s Doc Ock and he has that ego, he’s not going to try and just be Spider-man, he’s going to try to be the best Spider-Man ever,” said Slott.

Editor Stephen Wacker said that while Parker is gone, his permanence remains and his life casts a long shadow.

“His life is still important to the book because it affects everything that Doctor Octopus does as Spider-Man. Seeing a supervillain go through this life is the point — trying to be better than the hero he opposed,” Wacker said.

“Doc has sort of inspired by Peter’s life. That’s what I mean when he talks about the shadow he casts,” he said.

The sentiment echoes what Uncle Ben said in the pages of “Amazing Fantasy” No. 15, Slott said.

Editor Stephen Wacker called it a fitting end to the old series, which sets the stage for a new one — “The Superior Spider-Man” early next year — because it brings Peter Parker full circle, from the start of his crime-fighting career to the end.

“In his very first story, his uncle died because of something he did so the book has always been aimed at making Peter’s life as difficult as possible,” Wacker said. “The book has always worked best when it’s about Peter Parker’s life, not Spider-Man’s.”

And with Octavius influenced by Parker’s life — from Aunt May to Gwen Stacy to Mary Jane — it will make him a better person, too.

“Because Doctor Octopus knows all of those things and will make decisions on what he saw Peter going through,” Wacker said. “In a way, he gets the ultimate victory as he becomes a better hero.”