'Rookie Blue': Charlotte Sullivan on Gail's New Romance, 'Gut-Wrenching' Finale

Rookie Blue Charlotte Sullivan Episodic - H 2013
Caitlin Cronenberg/ABC

New romances are popping up on Rookie Blue, but Nick and Andy's relationship is affecting Gail in a significant way.

"It's such a gamble, seeing as how both Gail and Andy work together each and every day, and certainly that relationship causes an interesting dynamic between Gail and Andy," actress Charlotte Sullivan tells The Hollywood Reporter. "It further deepens [Gail's] rage and insecurity."

Andy and Nick's blossoming romance continues to affect Gail in dramatic fashion. "Nick's left [Gail] before. This isn't the first time. It's painful," the actress says.

STORY: 'Rookie Blue' Renewed for Fifth Season at ABC

Don't expect the trio to come to an understanding any time soon, at least according to Sullivan. "She's completely gutted by it and has a hard time showing it for sure," she says.

The Canadian actress hints that with the fifth season on the horizon (production likely begins in 2014), Gail's search for her identity continues. "That changes things forever," Sullivan says. "You can't just go back to things being peachy keen after that. It's totally a shift in friendship, a shift in the group dynamic. Everything changes."

In the Sept. 5 episode, directed by star Gregory Smith (Dov), Gail's sexual exploration reaches new heights. Her current arc, Sullivan says, almost took place in season three. "My initial reaction was I didn't want to have two girls kiss onscreen [without it meaning anything]. It'd have to mean something," she explains.

Gail and Nick's breakup became the appropriate catalyst to kick off Gail's new story. "She's really insecure and has never really let her guard down with anybody and this beautiful creature, Holly (Aliyah O'Brien), comes along and allows her to open up," Sullivan says. "Gail is letting her guard down massively with this person. It's totally new and refreshing to play for me because I'm always playing the alpha in the relationship -- always upset, snarky and biting."

As Sullivan tells it, she isn't quite sure where the Holly and Gail pairing is headed -- and she prefers to keep it that way, at least for now. "What's exciting is the unknown," she says, "and allowing something to happen."

As for the end of the season, Sullivan teases that the finale will make you "want more," calling it "gut-wrenching." "It makes you go, 'OK, what the f---?' " she says with a laugh. "I remember watching it being, 'Ow, ow, ow, ow, ow!' "

Rookie Blue airs Thursdays at 10 p.m. on ABC.

E-mail: Philiana.Ng@THR.com
Twitter: @insidethetube