We know that there's a wedding in the works for Teresa Lisbon (Robin Tunney) and Patrick Jane (Simon Baker) on Wednesday's series finale of The Mentalist(8/7c, CBS), but will the couple actually make it down the aisle?

Though Jane is abducted by a serial killer in the first of two episodes Wednesday night (watch a sneak peek below), series creator Bruno Heller has all but promised fans a happy ending.

"We wanted to end as unironically and sincerely and as uncleverly as possible, with as much appreciation and thank you to the audience that have stayed with the show," Heller tells TVGuide.com. "So, ending with a wedding seemed like, yeah, why leave the audience wondering or guessing? ... I think there's a desire on the part of writers to be clever. We very much wanted to be sincere and right there with feeling and emotion, as opposed to being writerly about it."

Who died on The Mentalist? Victim and show boss speak out

Of course, it wouldn't be a Lisbon/Jane affair without a few bumps along the way - mainly in the form of the serial killer that the FBI is trying to track down.

"There's nothing generic about the wedding and the way it comes together," Tunney says. "It's the traditional ending with a twist. I think it really works, and it'll satiate the fans. And they're really who the show is for. They've followed us through many different time slots, days, everything. Hopefully we're going to give them what they want, and I think it does deliver. I was really happy when I saw it."

Adds Heller: "We had to balance what the show has traditionally done, and it's a murder mystery. ... We didn't want to simply abandon that to go for a romantic comedy."

Heller has spoken openly about the fact that, when he conceived of the show, he was firmly against the idea of bringing the two leads together romantically. And though this final season has focused heavily on them trying to feel their way through their new relationship, even Tunney says she was skeptical at first about ending the series at an altar.

Mega Buzz: Will The Mentalist's series finale be a happy ending?

"Initially, when I was told the idea, I was sort of scared," she admits. "Because it's a sort of thing where I wanted it to be original and organic and I'm like, really? This? Because I think Bruno, Simon and myself felt very protective over, this was seven years of our lives. How do we finish this? And how do we do the characters justice and also, at the same time, give the fans what they deserve?"

Whether or not Jane and Lisbon actually say their "I do"s has yet to be seen, but Heller confirms that fans can definitely expect the return of familiar faces, including Wayne Rigsby (Owain Yeoman) and Grace Van Pelt (Amanda Righetti), who left the show midway through Season 6.

But don't expect any references to Red John. The writers have very consciously strived for a lighter tone with the finale, according to Heller and Tunney.

"I think it's an optimistic ending to a show that wasn't always so optimistic, that had a lot of darkness to it," Tunney says. "I'm really proud of it because it's funny and it's not sappy. It doesn't underestimate the audience at the same time we're giving them something that's traditional. It doesn't seem hokey and it doesn't seem forced."

TV's most memorable series finales

"We started with a serial killer and we finish with a serial killer," she continues. "From the start, I think the reason why people were drawn to [The Mentalist] was, it was a show that was able to navigate this dark history of this character and this looming serial killer... but the way people treated crime scenes and spoke to each other and all that stuff, there was a lightness to it. I think that it's the perfect finale, tonally, for how we started the show."

The Mentalist series finale airs Wednesday at 8/7c on CBS. Check out an exclusive sneak peek below.

(Full disclosure: TVGuide.com is owned by CBS.)