It looks like Gilles Marini is not only joining the Brothers & Sisters cast as a regular, he may be doing so as one of the talented ensemble's most prominent characters.

With Rob Lowe set to bolt, his character, Robert, and wife, Kitty (Calista Flockhart, who will be missing a number of episodes next year) will no longer be the go-to couple.

So if the McAllisters are out of the picture, where - and when? - does that leave the rest of the Walker clan? Gilles says the show may jump ahead one year this fall.

Gilles Marini as Brothers & Sisters' Luc.

When it returns, under this theoretical flash forward scenario, Marini's Luc Laurent and Rachel Griffiths' Sarah would be more established - and central to the show.

“Hopefully, Luc by then will be in deep with the family, and his big heart will help them,” says Gilles. Which begs the question: What would his big heart help with?

Possibly something to do with Lowe's departing U.S. Senator, who, Gilles ominously teases “is offered a massive new opportunity, and then something happens.”

Whatever it is, that sounds like it's something bad.

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.