This three issue limited series recounts one of Ben Reilly's "lost" adventures that took place during his roughly 5 year long period of exile between his presumed death in Amazing Spider-Man #149 and his return to New York in Web of Spider-Man #116. It is a murder that occurred in this story that would later get Peter arrested in Amazing Spider-Man #400. This story is meant to be read after "The Trial of Peter Parker" crossover since Kaine's identity (first revealed in that storyline) is mentioned in Lost Years which is a story narrated with knowledge of that "present time" in the Spidey comics. Otherwise you don't need to read any clone saga issues as Lost Years is a self contained story.
If you want to read Ben's story from the beginning then start with the backup story "The Double" in the flipbook editions of the "Power & Responsibility" crossover and then the three part backup story titled "The Parker Legacy" which appeared in Amazing Spider-Man #400, Spider-Man #57 and Spectacular Spider-Man #223 before you read Lost Years. Alternatively you can read Lost Years #0 which reprints all those stories. Again not absolutely necessary but it provides good background for this story.
Lost Years takes place about three years into Ben's exile. Believing himself to be a clone he's a lone nomad who reluctantly helps people from time to time during his wanderings. Unbeknown to Ben, Kaine has been shadowing his trail wishing only to see him suffer.
Ben tracks down the car holding Raven and rescues him. The cops arrive soon after and Kennedy informs Raven about his wife and son in the hospital. While his son survives, his wife dies leaving Raven devastated and unable to face his son who gets kidnapped from the hospital.
After teaching a class, Ben runs into Janine on campus, he apologizes for missing their date (from issue 1) and despite her being icy at first Ben asks her out to dinner again which she refuses instead suggesting they go for lunch right at that moment. Ben and Janine get along well both feeling as if they are old friends who've known each other much longer than they have. Because of Janine, Ben becomes more hopeful and happy. He also begins to play hero again waging a one man war on Tannen's mob.
Kaine and Kennedy are outside looking at the stars. Each express similar sentiments of being inextricably attracted to each other. She is his light while he is her darkness. Their relationship has progressed giving Kaine hope as Kennedy expresses her love for him. A week passes and after sharing a passionate kiss, Janine tells Ben that this can't continue. Kaine while making love to Kennedy has an episode of painful spasms due to his celluar degeneration and jumps out a window.
Ben is upset but unsurprised by Janine's actions and proceeds to a warehouse to bust up a drug operation that's being overseen by Jimmy. Ben easily takes out most of the goons but is interrupted by a surprise attack from Kaine who beats him senseless and disappears. Ceasing the opportunity Jimmy points his gun at Ben but Kennedy intervenes only to point her gun at Ben. Also emerging from the shadows is Tannen, seemingly out of jail, with Raven's son.
This middle installment offers more character introspection and less plot. Ben, Kaine and Raven are flawed and conflicted characters. Ben wrestles with his power and responsibility to use it to help people. Kaine wonders whether a hideous monster such as himself can actually attain happiness and love. Raven having always upheld the law questions his faith in God after losing his wife.
There's a coloring error on one page (at least in the TPB version) which mistakenly uses the same color for Raven's monologue that is reserved for Ben but you should figure it out easily if you're paying attention. The coloring, in general, is pretty well done in this series except for some rather poorly done dithering used to create light shadows. Kaine becomes even more disfigured due to his cellular degeneration. Unfortunately, how JRJR chooses to draw his face after this resembles more a random mishmash of black lines than an actual disfigured visage. It's pretty lazy and difficult to discern Kaine's facial expressions.
3.5 webs for the series. It's worth a read even if you're anti-clone and a must-read for Reilly fans.