Chandler Riggs as Carl Grimes in “The Walking Dead.”

And then there was one. Or soon there will be one. Just one.

By now you should know which one — if “you” are a fan of “The Walking Dead.” An original character will leave by the start of the second half of the current season, the eighth, which picks up again in February, leaving but one.

This character was one of the first to appear all those seasons ago, and is one of the last two remaining from the pilot episode. He’s been critical to the series, critical to its success, and now critical — in some fashion — to the future. He grew up on the show, and fans saw him grow up. Even his hair grew long.

Spoiler alert: His name is Carl.

It’s not much of a spoiler. The Dead Nation has been buzzing over this since the midseason finale, but the buzz is now a roar. Why Carl? Why him? Carl Grimes (Chandler Riggs) lives on in Robert Kirkman’s genesis material, the comic book series, to fight other battles, to meet other survivors. Along with his dad, Rick Grimes (Andrew Lincoln), he’s the one unbreakable link back to the beginning — those halcyon pre-Negan days when the biggest and only threat was wandering herds of Walkers. Carl told his dad Sunday that he had been bitten by a walker, then showed the rest of us the chew marks. His final moments arrive Feb. 25.

Carl’s been a pivotal character. Once a symbol of innocence in a fallen world, he, too, then became one of the fallen, who killed his own mother (of necessity), his father’s former partner Shane (ditto) and one of the show’s most beloved characters (Dale). “Ruthless” supplanted “innocent.”.

Why Carl? Why now? There are the usual reasons — ratings — and more subtle ones. To breach Kirkman’s universe allows “TWD” to strike out on its own, at least to some degree. That opens up new vistas, new surprises. His exit also portends the eventual exit of Rick, although expect to have that play out over a couple of seasons as opposed to one. There remain two other originals from the first few episodes back in 2010 — Carol (Melissa McBride) and Daryl (Norman Reedus) while the last of the premiere episode survivors (Lennie James’ Morgan Jones) is headed to “Fear the Walking Dead” next season. Carol and Daryl can’t be feeling too optimistic about their futures.

Fans can be excused for interpreting Carl’s endstory for what it might superficially appear to be. After all, “TWD” has long used popular characters as cliffhanger bait.

Could this be another bait-and-switch — one of those cheap stunts that spike the numbers but inflame the base? Could he survive? That seems unlikely because Riggs himself confirmed his departure in a handful of interviews, notably saying this to the Hollywood Reporter: “Scott (Gimple, the executive producer) was trying to figure out how to bridge the gap between Rick not wanting to kill Negan (Jeffrey Dean Morgan) and Rick also really wanting to kill Negan, which he does. Scott’s way to get around that was to make Carl this really humanitarian figure and person who could see the good in people and see that people can change and not everyone out there is bad.

As Carl said to his father on Sunday, it’s about “finding some way forward, that’s how it’s gotta be . . “ Could Rick become a “humanitarian” in a storyline that doesn’t include his son as sacrificial lamb? It remains to be seen how Carl’s exit will be structured in February before that has an answer — a plausible or implausible one.

But this time it’s different, and must be. Carl — once the future of the show, assuming Rick died — can now literally save “The Walking Dead” from an eternity of repeat narratives, circular storytelling and a numbing deja-vu-all-over-again cycle that includes lots of guns, lots of walkers, lots of bad guys and lots of violence. In death maybe Carl can change the show — break that mold, change that future, change Rick, and even make “The Walking Dead” watchable again.

“TWD” needs a reboot, or at least a redirection. It too needs to find a way forward. Sorry Carl, but you’ve been elected to help find it.