Call the Midwife's Stephen McGann has revealed a hidden Easter egg in episode five that foreshadowed the devastating train crash in the series finale.
MORE: Call the Midwife's Stephen McGann shares personal trauma after heartbreaking finale
Taking to Twitter on Monday night, the actor posted the following tweet: "Bonus prize for spotting the *intentional* Easter egg in the end sequence of Episode six."
WATCH: What did you think of the series finale?
He then commented on the same post, sharing a clip posted by the show's official account earlier this month, before the fifth episode was aired. The clip shows Dr Turner's son, Teddy, playing with a toy train.
Fans were left shocked by the hidden warning and took to the comments section to praise the "sneaky" hint. One person wrote: "That’s very sneaky I must say I only noticed it the second time around," while another added: "It was all foreseen!!!! Very sneaky."
MORE: Call the Midwife fans point out clever Easter egg in series finale
MORE: Call the Midwife viewers 'in tears' following emotional series 11 finale
Other fans expressed their surprise, with one person commenting: "OMG THE TRAIN," while another added: "Omg - Teddy’s playing with a toy train."
Stephen McGann revealed the hidden warning on Twitter
Series 11 of the beloved BBC period drama came to a conclusion on Sunday night in what turned out to be an emotional rollercoaster of an episode.
For most of the series finale, viewers were unsure if Sister Julienne and Dr Turner would make it out of the train crash alive. It was a close call for the fan favourite characters with the former suffering a heart attack and the latter sustaining a head injury.
All was well in the end with the two characters safe and sound, but it was a bittersweet final episode as one of Nonnatus House's patients, Mrs Corbett, lost her husband to the crash while giving birth. It was revealed that Lionel Corbett had lost control of the train after suffering a loss of consciousness due to a brain tumour, resulting in the crash.
Call the Midwife will return with a Christmas special
Fans praised the emotional episode on Twitter following its release. One person tweeted: "Pfew @CallTheMidwife1 I’m a total mess again. How is it possible that I’ve been crying and laughing and crying and laughing for 11 seasons straight?" while another added: "That was a beautiful, emotional and really special episode of Call the Midwife. I needed lots of tissues."
Fans won't have to wait too long to catch up with residents of Poplar as the series will be back for a Christmas special in December. The show's official Instagram account announced the news, posting: "Thank you all for watching Call the Midwife Series 11! We'll be back!! Call the Midwife will return with a new Christmas Special and Series 12 in 2023."
Like this story? Sign up to our What to Watch newsletter to get other stories like this delivered straight to your inbox.