While "Riverdale" is scrambling to figure out who murdered Jason Blossom (Trevor Stines), there are even more secrets in play and they're going to come crashing down around his sister Cheryl (Madelaine Petsch) when the CW series returns on March 30.

While Petsch admits that Jason keeping his reasons he was running away from Riverdale, and the fact that Polly was pregnant, secret from her was hurtful, there are still a few secrets he kept still to be discovered.

"Later on in the season you find out more that he didn't tell her -- and that just rips her to shreds," she says.

tiera skovbye madelaine petsch riverdale thecw Riverdale: Jason has more secrets that will rip Cheryl to shreds

What could those secrets be, though? Given that Jason was involved in far more than he ever let on to anyone -- hence the car full of drugs that Betty (Lili Reinhart) and Jughead (Cole Sprouse) found -- the possibilities are endless. Of course, none of that will change how Cheryl feels about Polly and her brother's unborn child, though.

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"The minute she finds out Polly's pregnant, [Cheryl] just wants that baby. She just wants to take care of it, love it, because that's her one avenue to Jason now," Petsch says. "And it's the same with Polly. Eventually you'll see us team up... She will be a bit of an ally there."

The question is who she'll be opposing when teaming with Polly. The Blossom family immediately comes to mind, as they aren't the most nurturing bunch, but according to Petsch the Polly and Cheryl pairing is "not necessarily against my parents."

So who's the threat -- and what else was Jason hiding? That all remains to be seen. In the meantime Cheryl's priority is clear.

"She puts the baby first. But she also wants to protect Polly, because she's someone Jason loved so much," Petsch says.

RELATED: A ‘Riverdale’ dossier: Let’s figure out Jason Blossom’s killer

Watch out, Cheryl: :You might just lose your mean girl reputation with all of this love and protection you're slinging around...

"Riverdale" airs Thursdays at 9 p.m. ET/PT on The CW.

Posted by:Chris E. Hayner

Chris E. Hayner is equal parts nerd, crazy person and coffee. He watches too much TV, knows more about pro wrestling than you do and remembers every single show from the TGIF lineup. You may have seen him as a pro-shark protester in "Sharknado 3." His eventual memoir will be called "You're Wrong, Here's Why..." TV words to live by: "I'm a firm believer that sometimes it's right to do the wrong thing."