Based on the graphic novel, The Secret Service, by Mark Miller and Watchman artist, Dave Gibbons, Kingsman: The Secret Service tells the story of Eggsy, a young man who wasn’t born into money but grows up to become a gentleman spy. This past weekend, Kingsman: The Golden Circle arrived in theaters, but today’s list focuses on the first film, and how it adapted the plot of the text to suit its big screen needs.

The casting of the movie adaptation is spot-on: Taron Egerton as Eggsy. Colin Firth tapping into some inner-James Bond to play the part of Harry Hart. These are the characters fans will remember best from reading the comics, but their memories may begin to fail them when attempting to recall just how these characters know each other and interact within the source material. In this area, the film’s taken some turns since its comic days, so in order to better track where the biggest differences lie between the two mediums, here is a [SPOILER-filled] list of Secret Service’s biggest digressions.

One note in advance: Harry Hart from the movie, and Jack London in the book, aren’t exactly the same character (and their names aren’t remotely similar), but they do fulfill the same role as Eggsy’s Kingsman mentor, and have enough overlap in their stories to justify comparison.