How long can a zombie hobble along before one of the world's few remaining survivors finally puts it out of its undead misery? Since debuting in 2010, The Walking Dead has been a force to be reckoned with on TV. It's broken TV ratings records, become a pop culture phenomenon, made stars of practically its entire cast, and brought an entire genre back from the dead. All good things must come to an end, though, and one of those things is The Walking Dead.

As the AMC series prepares to storm San Diego Comic-Con to give the first taste of Season 9--which won't premiere until October--there are some massive questions looming over The Walking Dead. In particular, fans are wondering about the status of star Andrew Lincoln. Warning: The Following contains The Walking Dead Season 8 spoilers.

It was reported in May that Lincoln, one of the few remaining original cast members, was set to exit the show during Season 9, though AMC has yet to comment. And he's not the only one looking for a way out. Lauren Cohan, who joined in Season 2 as Maggie, is starring on ABC's Whiskey Cavalier this fall, which should keep her plenty busy and not nearly as available for The Walking Dead.

Rick (Lincoln) and Maggie leaving are just the latest in a long list of reasons I have been ready to quit The Walking Dead over the years. In the past, though, the show has always been able to find a way to reel me back in. Since the arrival of Negan (Jeffrey Dean Morgan), though, it's hard to find a light at the end of the tunnel.

At The Walking Dead's lowest points, fans of the comics would always point to the eventual arrival of Negan, the biggest villain of the franchise, as when everything would turn around. After all, Negan is the most devious and disturbed baddie The Walking Dead could ever think up on the page--seeing him in live action was going to be amazing. Even Glenn's (Steven Yeun) fake death in Season 6 could be forgiven because Negan's arrival was at hand.

Then he arrived, though. The whispers of Negan and peaks at his Saviors were a terrifying new thrill for the show. The man, himself? Not so much. While Jeffrey Dean Morgan is certainly a good choice to play Negan, the moment he stepped out of his trailer with trusty Lucille at his side and said, "It's gonna be pee pee pants city here real soon," something felt wrong.

That is a line pulled directly from the comic books, but seeing a live person say it in an actual life-and-death situation made the moment feel like a cartoon. It's not exactly the introduction fans needed as Season 6 came to a close and the show failed to reveal his first victim.

Then Season 7 arrived and he took out two beloved characters--Glenn and Abraham (Michael Cudlitz)--in the most graphic manner possible. Even for The Walking Dead, watching Negan repeatedly smash his bat into an already crushed head was too much. The show had crossed a line it hadn't until that point and took on a lot of criticism over it.

From there, the next two seasons featured the group constantly at odds with Negan, as new allies and foes were introduced. Those episodes saw Morgan chewing scenery as the bat-wielding maniac at an alarming rate. Long scenes were devoted to Negan monologues, as life during a zombie apocalypse somehow became more hopeless.

Now, after Season 8 and the supposed defeat of the leader of the Saviors, what's left? While The Walking Dead's ratings are still impressive, they've been sliding for some time. The Season 8 finale was the least-watched since Season 1--before the show found its massive audience. The more telling number, though, is that the Season 8 finale brought in 30% fewer viewers than Season 7's, one year before it.

There's a reason Lincoln and Cohan are looking for their exit strategy from The Walking Dead. The show's best years are behind it.

In theory, the show could go on forever. New characters are continually introduced and integrated into the group that could power the story going forward. However, fans just don't identify as closely with them as those introduced during the glory days. While viewers like Jesus (Tom Payne), he doesn't hold a candle to Michonne or Eugene (Josh McDermitt).

So what is AMC to do? It could continue milking The Walking Dead until it runs dry. After all, the network doesn't have a more popular property at this point--sorry, Fear the Walking Dead. When shows stay past their welcome, though, fan sentiment can turn swiftly. Nobody talks about the glory days of Season 25 of The Simpsons. Likewise, the later iterations of 24, Prison Break, Weeds, and even How I Met Your Mother are often looked back on with a frown. For many shows that overstay their welcome, the fanbase simply moves on.

With its ratings on the downswing, that seems to be what's happening with The Walking Dead. Now that Lincoln and Cohan--two big pieces of that show's heart--seem ready to move on, perhaps this year's San Diego Comic-Con is a great place to announce a final season. After all, doesn't this world and these characters deserve a proper farewell?

That's not going to happen, though. After all, while the ratings are tumbling, they're still impressive. The Season 8 finale brought in nearly 8 million viewers--compared to over 11 million in Season 7--which is still very respectable for cable TV. The Walking Dead may not be breaking records anymore, but there is a base of die-hards that will not give up on the show, no matter what. And with the reports that AMC is negotiating with Norman Reedus (Daryl) to keep him on as a major part of the series, the network clearly isn't planning on pulling the plug anytime soon.

Perhaps that's a good thing. Maybe The Walking Dead will find its way and become thrilling once again. With longtime writer Angela Kang taking over as showrunner in Season 9, that's certainly a possibility and hopefully, it is how this plays out. Because as it stands now, The Walking Dead remains a zombie, lumbering along and waiting for someone to finally put a bullet in its head.