The thirteenth episode of the second season of “The Walking Dead” is a particularly noteworthy hour, as it was the one wherein Rick revealed to the group that it’s not actually a bite from a zombie, per se, that turns one into a zombie. “We’re all infected,” Rick told the group. “At the CDC, Jenner told me. Whatever it is, we all carry it.”

In other words, *anyone* who dies in the world of “The Walking Dead,” unless that death causes their brain to be destroyed, will return to life as a walker. We’ve seen this exact sort of scenario play out before, perhaps most notably with Shane; Shane was stabbed in the chest by Rick, and soon thereafter re-animated as a zombie.

But we’ve also seen bites turn humans into zombies, right? Well, not exactly. We have indeed seen several characters die after sustaining zombie bites, but it’s actually been the infection and/or loss of blood, brought on by those bites, that has ultimately killed them. So it’s not the bite that infects characters in this world with the “zombie virus,” so to speak. Rather, they’re all already infected with the airborne virus, doomed to the fate of returning to life as flesh-eaters whether they die from a bite or heart attack.

That’s all pretty easy to wrap your head around, but why then did a character like Carl have to die after being bitten by a zombie? The bite itself wasn’t severe enough to cause Carl to bleed out, but the infection that the bite caused did end up taking Carl’s life. With the right antibiotics, given what Carl’s own father told us about the pathology of the virus back in Season 2, couldn’t Carl’s life have been saved? If the infection that the bite caused had been cleared up with the proper medicine, couldn’t he have survived?

Knowing what the show has told us, and knowing what Rick himself most definitely knows, why did Rick not at least make an attempt to get the infection under control?

In the wake of this past Sunday night’s episode, I find myself even further confused about the pathology of the virus. Last night, we saw that Father Gabriel has been infected by what appears to be a lesser form of the zombie virus, presumably as a result of his recent exploits with the show’s patented “zombie cloaking device” technique; Gabriel and Negan covered themselves in walker guts to avoid detection, which seems to have passed some sort of infection into Gabriel’s bloodstream. Not, however, into Negan’s.

Gabriel has been slowly dying from the infection, and last night he was rendered almost completely blind cause of it. And yet, the infection isn’t going to actually kill Gabriel, it seems, as happenstance (or perhaps it was a divine act from God himself) led to him stumbling upon a couple bottles of antibiotics. It seems the antibiotics will get Gabriel’s infection under control, at least for the time being, thereby saving his life. So if antibiotics can save Gabriel from zombie-transmitted infection, why not Carl?

To add even more confusion to this whole thing, the episode ended with Negan devising a new plan of attack. Partially inspired by Gabriel’s health troubles, Negan realized that the blood of zombies can be used to intentionally infect his adversaries. The Saviors are going to coat their weapons in infected zombie blood, allowing them to administer “kisses of death” at their leisure. Presumably, this form of infection will play out similarly to Gabriel’s, rendering untreated victims sick, blind and, eventually, dead.

Negan told his group, “You all know how it works. You get a bite, some kind of wound from one of these things, something from them gets in you, and you die.”

But wait a second. Didn’t we learn in Season 2 that EVERYONE is *already* infected, the virus inside of them only triggering upon their death? If that’s the case in the world of “The Walking Dead,” then why is Gabriel even infected after playing around with zombie guts? Similarly, why would a stab from a zombie blood-covered knife do anything more to a human character than a stab from a knife *not* covered in zombie blood? Well, according to what the show has shown us in the recent past, it actually wouldn’t.

Not only have characters multiple times rubbed zombie blood and guts all over themselves, without getting infected, but you may remember an incident involving a machete and Rick’s hand back in Season 6. In that season’s third episode, titled “Thank You,” Rick cut his hand on a machete that was literally embedded inside of a zombie. The machete was no doubt covered in that zombie’s blood, which presumably got into the fresh wound on Rick’s hand. Alas, however, Rick never got infected.

So again we ask, how exactly does one get infected with the zombie virus on “The Walking Dead”? Is every remaining human on the planet, as revealed in Season 2, already infected, or does it require a bite and/or zombie blood entering one’s bloodstream in order for one to become infected? If the former is the case, Gabriel’s infection doesn’t make much sense, nor does Carl’s 100% unavoidable death or Negan’s new plan. These continuity issues date back much further, as you surely remember Hershel’s leg being cut off in order to stop the spread of the infection after he was bitten back in Season 3. You could argue that zombie DNA exacerbates the infection already inside everyone, but again we point to the incident involving a machete and Rick’s hand.

Are we missing something or are the rules ever-changing to fit current narratives?