As The Mentalist moves to resolve the Red John saga for good, the relationship between Patrick Jane (Simon Baker) and Agent Lisbon (Robin Tunney) will fall under considerable strain.

While the duo has weathered five seasons of sexual tension, what will their dynamic be like once Red John is taken care of?

Agents Grace Van Pelt and Wayne Rigsby to Leave The Mentalist.

"I think they absolutely love each other," said series creator Bruno Heller, according to TV Guide. "Have they ever laid there at night and thought about the other one and what that would be like to be a romantic couple? Of course they have, and that's exactly what they're going to continue feeling and thinking."

However, there are several events that could serve to tear the pair apart. Jane's desire to kill Red John, a new female lead, and divergent philosophers on how to capture the serial killer have all be posited as possible conflicts for the partners.

Two New FBI Agents to Join the Cast of The Mentalist.

They care so much about each other, [but] with the stakes being ratcheted up by Red John being ever-present, it's a pressure-cooker situation," Baker told TV Guide. "They have to lean on each other more, but it's also going to be easy for them to blow each other's fuse."

The Mentalist returns to CBs on Sept. 29.

See Jane react to Lisbon's former fiancee

Tags: The Mentalist