'Call the Midwife' Season 4 Spoilers, Cast Rumors: 2 New Characters Set to Arrive, More Changes Coming

There aren't too many details being given about the upcoming fourth season of the hit period drama series from BBC, "Call the Midwife." However, current cast rumors indicated that there will be two new characters that are heading to the show.

Two nurses will take their places in the series following the exit of Jenny Lee (Jessica Raine) and Cynthia Miller (Bryony Hannah), according to Radio Times. The two newcomers are Charlotte Ritchie, who will play as nurse Barbara Gilbert, and Linda Bassett as Nurse Phyllis Crane.

Ritchie's Gilbert will start off with some drama but will be followed with some positivity thereafter.

"She begins quite badly and sort of redeems herself later on," Ritchie told Enstarz. "She has a couple of really tragic moments which is awful and then she kind of gets into her stride a bit more- but she still continues to make mistakes along the way."

As for Bassett, the actress also revealed some details.

"I was delighted to be offered the job," she said. "I was born in the 50s so it's fun to work in a period that I can remember and know so much about."

Carter Matt revealed that fans will see a period of transition when the show returns to the small screen for the fourth season. Show creator Heidi Thomas said there will be changes as the season progresses.

"The world didn't go from black and white to colour at midnight on the 1stJanuary 1960 … Throughout the series we've been addressing this very slow and gradual progression of social change, which ultimately will ignite into something much bigger in the middle of the 1960s," Thomas said.

"Call the Midwife" Season 4 returns early in 2015.