If you could go back in time, would you kill Hitler? Would you stop a murder, a fire, or the collapse of a family? Would you change the past to make a better future?

These moral and technical implications of time travel are tackled in the novel-turned-miniseries 11.22.63, written by horror mastermind Stephen King and adapted for TV by JJ Abrams. The series follows a recently divorced English teacher, played by James Franco, who discovers a time portal to the year 1960. Franco journeys back in time to live in the past for three years and prevent the assassination of John F. Kennedy.

Each episode tackles different obstacles in the journey to discovering JFK’s killer. The past itself resists change, throwing seemingly random, dangerous hurdles at anyone who attempts to alter history.

Despite a compelling premise, the series wanders without focus at times. With only one goal for an entire series, it can be difficult for episodes not to feel drawn out. Luckily, the writers seem to have anticipated this issue–side characters and a risky romance push the story along.

A mostly unheard-of cast adds a level of reality to the far-fetched plot. Besides James Franco, whose reliable performance as a troubled, intelligent do-gooder will surprise no one, other characters shine through. Franco finds a sidekick partway through the series in Bill Turcotte, a traumatized teenager played by George MacKay. It’s hard to look away from MacKay’s earnest and passionate performance.

11.22.63 will entertain history buffs and Stephen King fans alike. Despite an occasionally outdated execution, the chemistry between characters and mysterious plot feels fresher than any other recent series. The entire show is available for streaming on Hulu.