Robson Green is back in character as DI Geordie Keating – trench coat and all – but on Tuesday, he found himself struggling to concentrate on set. Sharing an update on Instagram, the Grantchester star revealed that the crew had rocked up in their Halloween costumes, making filming particularly "surreal".
Posting a behind-the-scenes photo, Robson and his co-star Rishi Nair could be seen interviewing a mystery suspect, while members of the crew looked on in spooky outfits. One was even dressed as the killer clown, It, and sported a full face of makeup.
"Started rehearsals this morning and all I could think of was that a lot of the production team drove to work at 6am dressed like that!" joked Robson. "Solving crimes today was slightly surreal! Happy Halloween."
Shortly after posting, the 58-year-old was inundated with comments from fans. "How many takes did you have to have as I'm sure it was a laugh," wrote one. "That is hysterically funny!!" added another. Meanwhile, a third penned: "Brilliant. Happy Halloween to you & yours."
Robson's colleague Rishi was equally distracted by the array of costumes. Posting the same photo on his Instagram stories, the actor captioned it: "New challenge unlocked, trying to film serious scenes when the crew are dressed up like this."
It's been a busy few weeks for Robson and Rishi as they continue to film the latter half of Grantchester's ninth season.
In a recent Instagram post, Robson raved about his new co-star, who has taken on the role of Reverend Alphy Kotteram.
"A joy to be working alongside fellow actor and now friend @rishinair," began Robson. "Whether we're rehearsing, filming, or simply sharing a conversation during breaks, his presence never fails to lighten the mood and create a warm and supportive atmosphere on set.
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"His humility serves as a reminder to all of us that no matter how far we may go in our careers, it's essential to stay connected to the people and experiences that shape us."
Clearly the feeling is mutual as Rishi has also raved about Robson in social media, writing: "What an absolute joy it has been working with this man on a daily basis for the past 4 months.
"His generosity, guidance and kindness has allowed me to be the best I can be on this job. An extremely talented, hard working and giving actor and now a great friend. I've been absorbing and learning as much as possible. Sometimes in life, be a big yellow sponge."
While little is known about season nine of Grantchester, Rishi's character Revered Alphy will end up working with Geordie when an intruder breaks into the vicarage. According to Masterpiece's website, Alphy "has an instinctive distrust for authority and absolutely no desire to get involved in murder investigations".
The synopsis continues: "But Alphy and Geordie will discover they have a lot more in common than they first think, and Alphy will find that in Grantchester, murder is never far away. From deadly circuses, abandoned babies, and hostile historians to vanishing valets and murderous satirists, Geordie and Alphy witness first-hand how religion can be corrupted, but also how faith, love and friendship can offer hope – and renewal."