The fourth and final season of Killing Eve debuts this Sunday on BBC America and AMC+, and it kicks off with Jodie Comer‘s assassin character, Villanelle, attempting to become “good” by, of all things, joining a church. Laura Neal, the show’s lead writer and executive producer, tells ABC Audio that the big theme this season is whether or not people are actually capable of change.

“Can Villanelle really change? Can she become a good person after all this time of being, you know, a murderous psychopath?” says Neal. “And likewise for [Sandra Oh‘s ex-intelligence agent] Eve — she hasn’t been a murderous psychopath, but can she become somebody who can do very dark things and be very self-serving?”

But this season’s big challenge, Neal notes, was creating an exciting plot that would also lead to a satisfying series finale.

“We did have a sense of where we wanted these characters to end and how we wanted their stories to kind of collide,” she says. “And then, of course, you have to make each episode thrilling and include all of those things that the audience of Killing Eve has come to expect — like fun murders and amazing costumes and amazing locations.”

Neal adds, “We definitely had to balance the overarching intention for the series with the individual episodes, and making those feel fun and light and not too weighed down by the expectation of the ending.”

So what about that ending?  After all Villanelle and Eve have been through, will they end up together?  Neal shares what she says when people ask her.

“I stay very tight-lipped,” she laughs. “I normally say, ‘What do you think happens?’ and then I mine them for ideas!”

The eight-part final season of Killing Eve debuts at 9 p.m. ET/PT, and encores Monday on AMC at 9 p.m. ET/PT.