Sister Julienne and Dr. Turner are in danger.

Call The Midwife creator Heidi Thomas has warned fans about the upcoming season finale. Last Sunday, Dr. Turner, Sister Julienne, and Nurse Nancy were involved in a train accident. The shocking crash left viewers completely speechless and on the edge of their seats. We all couldn't help but wonder who will survive? Nancy managed to flee the carriage, but Sister Julienne and Dr. Turner were still on board when the evacuation took place. Both major characters were unconscious towards the end of the episode, but fans will have to wait until this weekend to see who survives. Series writer Heidi Thomas teased the finale. She told RadioTimes that viewers ought to have plenty of tissues ready. "The thing is, if there was a train crash near where you live, in the world of Call the Midwife, the two people you could rely on to come and sort everything out are Dr. Turner and Sister Julienne." "But if they are in the eye of the storm, who will save them?" she asked. Heidi said she is always willing to take risks as a writer, which doesn't exactly make us feel great about the finale. Could we be bidding farewell to one of the show's most beloved characters? She said she is a "very daring woman". "What appeals to me as a dramatist isn't the spectacular nature of anything, but I know my Call the Midwife characters so well, as do the audience, so the idea of taking people with whom you're very familiar, and putting them in an unfamiliar situation, immediately creates all sorts of scenarios we don't normally get to see," she added. Call The Midwife finale airs on Sunday, February 19th at 8pm.