Call the Midwife has hinted that the upcoming Christmas special could be Sister Monica Joan's last.
In the festive episode, Sister Monica, played by Judy Parfitt, decides that she won't be alive to see the next Christmas, prompting her Nonnatus House friends to pull out all the stops in an attempt to lift her spirits.
The synopsis teases: "Sister Monica Joan (Judy Parfitt) is convinced this could be her final Yuletide and decides she'll not live to see man walk on the moon. The Nonnatus Family, including Trixie's (Helen George) brother Geoffrey (Christopher Harper), decide something must be done to try and lighten her state of mind."
This isn't the first time Sister Monica Joan's future at Nonnatus House has been left uncertain. Fans were seriously worried for the character in series 12, when she became gravely ill with a case of hepatitis.
Throughout the season, viewers watched as the beloved midwife grew more lonely as her fellow nuns started to neglect her.
Thankfully, it seems Sister Julienne is looking out for her in the upcoming festive special. Teasing the episode, actress Jenny Agutter said, per Digital Spy: "Winter is tough — something you need to get through, and Sister Monica Joan feels she's not going to get through it and won't be there next year.
"She is very low, very depressed, and it is up to Sister Julienne to help her see that there is no reason to believe these dark thoughts and that there is a great deal of vitality in her."
Elsewhere in the Christmas special, Nancy (Megan Cusack) decides to stay at Nonnatus House, while Trixie (Helen George) and Matthew (Olly Rix) prepare for their first Christmas as a married couple when they get an unexpected visitor.
Meanwhile, Cyril (Zephryn Taitte) gently intervenes when he discovers a lost soul living alone in a dilapidated basement flat, while Nurse Crane (Linda Bassett), who is away on her refresher course, faces heavy snowfall as she attempts to make it home in time for the festivities.
Speaking to HELLO! and other press about the festive special, Jenny said fans are in for an "extraordinary" ending as the community comes together.
READ: 10 Call the Midwife stars who left the show and why
"One of the things that fascinated me is because we've been away places such as South Africa and to the Outer Hebrides, and we've done a couple of them that have been very contained," she said. "It's always interesting to me that it can actually have so much within it when it's contained in that way. And how important the community becomes and how all of those stories weave together. It builds to an extraordinary end."
"The whole thing is about making that happen, and hope and love. It's lovely for so many of us, it's a special piece."