FP Jones is a changed man — or is he? That's the underlying question of tonight's all-new episode of Riverdale. Because as Jughead is about to discover, you can take the man out of the Serpents, but you can't take the Serpent out of the man.

In "Chapter Twenty-One: House of the Devil," the former Southside Serpents leader is finally out of jail and on parole, and he's more determined that ever to get his life back on track. More importantly, he's intent on giving Jughead the kind of stability he deserves. To celebrate FP's return, Jughead and Betty throw him a Southside Serpent retirement party at the Whyte Wyrm, a seedy bar on the south side of town.

"It becomes a very interesting party for many characters," actor Skeet Ulrich teased. While Ulrich wouldn't go into specifics, it's clear that FP is a ticking time bomb. He wants to be on the straight and narrow, but Jughead's decision to join the Serpents and to make a deal with notorious Snake Charmer Penny Peabody has thrown a wrench in his plans.

"[He's] certainly not happy at all," Ulrich said. "He wants a very different life for Jughead, and he senses that Jughead has the smarts to have a different life, to get out of that town and be something. That's what he's hoping for him."

After all, cleaning tables and sweeping floors at Pop's Chock'lit Shoppe isn't going to be enough to pay off his son's debts. "Being a felon, now he has even less opportunity, and it's almost forcing him to stay with the Serpents to keep paying the rent," he said. (Though, putting on that crisp, white Pop's uniform for the first time was a "jarring" experience for the actor.)

With Jughead caught in a heated "battle between blood and family," FP is forced to get his hands dirty. It's a vicious cycle, one that he was hoping to avoid this time around.

"I've always felt his intentions were purely to give Jughead a better life than he had," Ulrich said. "It's very frustrating for him that he can't necessarily do that."

In Season 1, FP tried to change and overcome his flaws to become the kind of dad he knew Jughead deserved. But he quickly learned that the town of Riverdale — with its white picket fences and wholesome Americana — was never going to let him change. So he reverted back to his old, woefully misguided ways.

Now, after serving time for his complicity in the murder of Jason Blossom, he's under the same notion that he can "clean his life up and make things work for himself and Jughead." But with the Black Hood Killer on the loose, putting the panic-stricken town on edge, he's not exactly being received with open arms in the community.

"It's interesting to see him bite his tongue on things," he said. "No matter what buttons are pushed, he has to walk the straight and narrow now. But we know he's also a very ruthless guy. I wonder if what's boiling underneath is going to come out in a ruthless way at some point."

Given FP's history of criminal activity, just how worried should he be about the serial killer who's made it his mission to expunge the town of all sinners? According to Ulrich, FP's got the same chance of survival as just about anyone else in town.

"I don't think anyone in Riverdale can escape some sort of murderous drama," he concluded.