The Walking Dead Season 4, Episode 2 Preview: A Look At 'Infection'

The Walking Dead returned last night, and one thing is evident. The prison isn't quite so safe, even if the fences are holding up. Spoilers, obviously, if you haven't seen last night's "30 Days Without An Accident" Season 4 premiere! In some zombie stories, the only way to turn is to be bitten. But if the rule is that anyone who dies will come back to life as a zombie, bitten or not, that means that unless you're locked up somewhere alone, you're always technically at risk of a zombie attack. It only takes one person dying for the enemy to be inside the gate, as evidenced by the end of last night's episode when young Patrick fell ill and died in the shower, turning into a zombie in the final moments.

Will Episode 2 ("Infection") pick up with Patrick tearing through the prison trying to eat his old friends? Seems very possible. And people might want to start sleeping with their cell doors closed from now on, just in case. Especially if there's some kind of sickness making the rounds that's killing pigs and people. In the meantime, the above promo, which teases the season ahead, indicates that there will be trouble on both sides of the gates. One of the issues at hand is Carl. In the preview, Rick is making it clear that "you don't fire unless you absolutely need to." And later he tells him, "Shoot or you run." Being really specific to Carl about when to use the gun and when to not shoot a kid in the head is probably a good thing, given the events of last season.

The clip below comes from Sunday's "Infection" and indicates that Carl's looking to get his gun back. Rick doesn't seem certain about that just yet. And then it looks like there's a problem…

"Walkers in D"!

I'm wondering if the walkers are Patrick's doing. Maybe we're wrong to assume Episode 2 will begin with mayhem. It's possible walker-Patrick will stumble around and get lost, then resurface later that morning. Or maybe he'll attack someone or a small group apart from the rest of the prison. With so many people now living there, it's entirely possible that he attacked someone and the rest of the prison has yet to discover it. That would allow for more than one walker to be lurking inside the prison by the time the situation becomes known. We'll find out Sunday night!

Finally, here's a look inside last night's "30 Days Without an Accident."

Read our full breakdown of the Season 4 premiere here.

The Walking Dead airs Sunday at 9:00 p.m. ET on AMC.