Warning: contains spoilers for Ben Reilly: Spider-Man #1!
Marvel's Spider-Man has seen his share of odd storylines, but his infamous Clone Saga ranks as one of the worst. Containing a cornucopia of confusing and convoluted clone-centric contrivances, the core concept was commendably compelling: what if Peter Parker was allowed to grow up without losing Spider-Man's core audience? The result was a mess of a storyline that even Marvel, as of Ben Reilly: Spider-Man #1, admits was a mistake.
Spider-Man owes his long-lasting appeal to overcoming the everyday challenges of being an adolescent while also performing the duties of a superhero. He's constantly struggling to pay rent, has difficulty maintaining relationships with Mary Jane and Gwen Stacy, and struggles to manage his time between work, studying, and superheroics. As a result, Marvel is very reluctant to allow Spider-Man to grow up; giving Peter a stable relationship and a promising future means losing his all-important relatability. Long-time fans of the character wanted Peter to grow, but Marvel wanted Spider-Man to remain a struggling, single mid-20s male. The company believed they could have their proverbial cake and eat it too with the Clone Saga and the clone in question, Ben Reilly.
Spider-Man's clone from a one-off story in the 70s was brought back to cause Peter no end of woe and misery. The story was written with the intention of eventually replacing Peter with Ben; the former would retire as Spider-Man to live a life with Mary Jane while the latter assumed the wallcrawler's role. Unfortunately, what began as a simple story quickly confused readers as editors mandated that a one-six-month storyline be expanded to over two years. As such, the writers threw multiple "shocking" plot elements at the story: killing Aunt May, bringing a third clone into the mix (Kaine), and finally revealing that Peter Parker was a clone and Ben was the original the entire time.
Ben Reilly: Spider-Man #1 summarizes these plot points in a few pages of narrative boxes, and it's clear that not even the core participant in the Clone Saga understands the story entirely. In particular, the decision to reveal Peter as the clone was loathed by the Spider-Man faithful. Writers quickly backtracked and re-revealed that Ben was the clone, but by now the story was so convoluted that no amount of retcons could fix the past issues.
Eventually Ben was killed (he got better in 2016's Dead No More: The Clone Conspiracy), Aunt May was brought back, and Peter never received his happy ending with Mary Jane. For many readers, it was as if the entire affair never happened. Aside from bringing Ben Reilly to the Marvel Comics Universe, the Spider-Man Clone Saga is a story that is best left forgotten.