The tension is rising on Riverdale as a masked man terrorizes the town. The pressure only increases this week as we find out why the killer is targeting Riverdale and who should be most afraid.

For better or for worse, Archie (KJ Apa) isn't willing to stand by and let this person make his family and friends feel unsafe. He's got the support of Reggie (Charles Melton) as he begins formulating a bold plan, but is Archie prepared for just how dangerous taking a stand against a killer can get?

TV Guide talked to Riverdale creator Roberto Aguirre-Sacasa about where Archie goes from here and who we should be worried about going forward.

From the preview we know that Archie is "taking things into his own hands." What can you say about what that means?
Roberto Aguirre-Sacasa: In a weird way, it really builds on the idea that that we built in the [season premiere]. At the end of the premiere, Archie sets up a milk crate with a baseball bat and says, "I'm going to stay up and protect my dad." What the last few episodes have taught him is that, "Oh wow, this problem is much bigger than my dad. There's a guy out there doing this." Archie, as athletic as he is, is not a superhero. He can only be in one place at any given time. How is he going to protect the town, his family, his friends, the school he loves? That's kind of his drive, basically. It comes from that need to protect everyone. It is building towards a darker story of almost vigilantism.

Ethel is back this week! How worried should we be about Ethel in this episode?
Aguirre-Sacasa: Listen, Shannon [Purser] has a history of playing fan-favorite characters that die suddenly and people get really, really upset. No one is safe in Riverdale. Yeah, I think people should be worried about Ethel. I think people should be worried about everyone.

Is Jughead Behind all of Riverdale's Sinister Mysteries?

Is there anyone we should be really worried about now that we have a killer after secret keepers and sinners?
Aguirre-Sacasa: What we'll discover and see in this episode a little bit is that people are starting to keep secrets from their friends and loved ones. Jughead starts keeping a secret from Betty in this episode. Absolutely, thematically we'll be exploring this terrain absolutely.

We were introduced to jingle jangle in the last episode. What can you say about how much of a problem that's going to be this season?
Aguirre-Sacasa: Jingle jangle is going to be huge problem this season. Absolutely, a huge problem this season. It's almost the equivalent of maple syrup last year.

Riverdale airs Wednesdays at 8/7c on The CW.

(Full disclosure: TV Guide is owned by CBS, one of The CW's parent companies)