Downton Abbey creator Julian Fellowes is hoping Shirley MacLaine will return to the show at some point.
The US actress played Cora, Countess of Grantham's (Elizabeth McGovern) outspoken mother Martha Levinson in the last series of the hit ITV1 period drama.
Asked if the Oscar-winner would make another appearance on the show, Fellowes said: "She will come back, I'm sure."
The writer said he was now "under the cosh" completing the scripts for the new series - which starts filming next month.
Viewers will see new mother Lady Mary Crawley (Michelle Dockery) as a widow after the shock death of her husband Matthew (Dan Stevens) during the Christmas special.
"I was very, very sorry Dan left," Julian said. "I thought he did a terrific job for us, I think he's a terrific actor.
"But actually, nothing is harder to dramatise than happiness. When two people are happy, that's it. That's why in the old movies, they don't kiss and marry in the middle, they kiss and marry at the end. Because in a way that's it.
"So now we've got Mary widowed, trying to control the estate, feuding with various other people about what the right way forward is, looking for a new life dare one say it. All of that is really more interesting than two people sitting by the fire having a cup of tea."