BBC The Responder fans were thrilled as they spotted a nod to The Office.
Martin Freeman stars as Chris Carson in the new six-part drama, which is based on former Merseyside Police officer Tony Schumacher's experiences working for the force.
The 50-year-old actor has enjoyed a meteoric rise to fame since he shot to stardom as bored office worker Tim Canterbury in the classic mockumentary series.
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He is playing an entirely different role in the BBC thriller as a morally compromised urgent response officer tackling a series of night shifts on the beat in Liverpool.
Martin's character is experiencing mental health struggles in the gritty drama as he tries to to juggle the pressures of the job while keeping his marriage together.
He is seeking counselling from a therapist in the show, but fans were thrilled during the emotional scenes as they spotted a Wernham Hogg reunion.
Chris' therapist is played by Elizabeth Berrington, who starred in The Office Christmas Special as pregnant office worker Anne.
She played Tim's overbearing desk neighbour - and prompted Martin to deliver his iconic bemused looks to the camera.
Delighted viewers took to Twitter to point out the "nod" to the iconic British sitcom.
Peter said: "Really liking Responder, great performances, gripping plot. Nice little nod to The Office aswell."
@Jazzypap commented: "Isn’t his therapist this woman who appeared with Martin Freeman in The Office?"
@Juniperdt added: "OMG The counsellor in #TheResponder is Tim's colleague from The Office. "Do you mind not smoking next to me? I am pregnant"
Matty posted a clip of the scene from The Office Christmas special and said: "Best scene on #theresponder so far"
The Responder continues Monday at 9pm on BBC One.
The full series is available on BBC iPlayer
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