With Breaking Bad over for good and Mad Men’s next season many months away, AMC’s focus has shifted entirely to its highest-rated original series: The Walking Dead, a post-apocalyptic zombie drama that has continued to attract staggeringly high ratings every year. The series, which is based on Robert Kirkman’s popular comic-book series of the same name, has thrived in part by following the blueprint set by the source material.

But it’s also worked by straying from it. Over the course of its past three seasons, The Walking Dead has gone out of its way to create characters and stories unique to the TV series. Fan-favorite characters Merle and Daryl Dixon were written expressly for the TV show, and the story has taken detours to places, like the Centers for Disease Control and Prevention, that were never a part of the comic's story. Glen Mazzara, who served as The Walking Dead’s showrunner last year, told Collider he considers the TV series to be an "alternate universe" to the comic.

Still, the TV show has always circled back to its roots; when David Morrissey was cast as The Governor, readers of the comic had a months-long head start over those who were solely watching the TV show. Last Sunday, 16.1 million viewers tuned in to see what had happened to series protagonist Rick Grimes and company since last year’s season three finale, which concluded with the villainous Governor still at large. For fans of the comic, the third season finale doubled as an abridged version of one of the comic's most memorable storylines, when The Governor led an assault against the prison that Rick and the other Atlanta survivors had turned into a makeshift colony.

If you’re familiar with the comic, you might have assumed that the premiere would begin by revealing that the prison had been destroyed, and that Rick was in a near-catatonic state out into the wilderness. It’s a story that fans first read all the way back in 2008, two years before the TV series premiered. But if you were expecting Rick to spend the better part of the season mourning his wife while traveling the countryside, getting mysterious phone calls along the way — well, that was so last season.

The greatest trick the original showrunner Frank Darabont taught the production crew behind The Walking Dead was to liberally adapt from the best of the 120+ issues still being pumped out by Image Comics. The recent news that the show’s creative team has cast Eugene and Abraham — two characters from the comic who appeared much later down in the road in the original storyline — is more proof that The Walking Dead can rely less on rehashing the comic's figurative moments than on crafting its own.

This season will even see the introduction of an original character Kirkman created as a stand-alone novel series that began with 2012's The Rise of the Governor. Will that mean a flashback episode? A totally different spin on the character? Could The Walking Dead’s fourth season tell the origin story of The Governor entirely through cold opens?

Why not? The success of The Walking Dead has shown that the plot works best when it doesn’t replicate the story beat-for-beat. It’s a pattern that The Walking Dead established from the beginning. Rather than stick to Kirkman’s original script, which killed off Rick’s best friend Shane within the first arc of the story, The Walking Dead kept Shane around for two whole years, offerings its own take on a once-familiar story.

The Walking Dead universe has shown that it can sustain all kinds of stories; a TV spin-off is already in the works, and an acclaimed video game adaptation has been ported to nearly every console and electronic device imaginable.

The ideal version of The Walking Dead is a show that would even use the knowledge of comic book fans against them. The show has already played with the audience's expectations of certain characters: T-Dog was long assumed by fans of the comic to be the TV show’s version of the popular character Tyreese — until Tyreese was suddenly introduced as a separate character in the third season.

These original characters and stories serve everyone involved with the series. Kirkman gets the chance to try out stories he never got to tell in the comic; the show’s creative team gets to put their unique stamp on the material; and fans who are already familiar with the story get to be as surprised as the audience watching it for the first time — if not more scared for having their expectations subverted.

Anyone who has read the comic probably knows that there are dark times ahead for Rick and company — but let’s hope the exact nature of those dark times turns out to be a mystery for all of us.