Call the Midwife drops blink-and-you'll-miss-it Doctor Who Easter egg

An unexpected choice indeed.

And you might have been surprised to learn that Sister Monica Joan enjoys watching Doctor Who in her downtime.

But with the Nonnatus House television on the blink and a shortage of engineers due to the ongoing strikes, she was unable to engage in her favourite pastime, leaving her downbeat.

"For now, I must endure," she said with the weight of the world on her shoulders.

But eventually, her patience ran out, and at the end of the episode, she gave the telly a good ol' thwack with her walking cane – and lo and behold, Third Doctor Jon Pertwee appeared.

In the episode depicted – the second of his first story, Spearhead from Space, which aired on 10th January 1970 – mysterious meteorite showers have fallen over a patch of woodland in Essex, which turns out to be energy units containing an alien entity with a taste for plastic – and big plans to take over the world.

Sister Monica Joan certainly wouldn't approve...

Pertwee led five seasons of the show from 1970 to 1974, during which time he dazzled audiences with his flamboyant charm, before stepping aside for Tom Baker.

He was also the first Doctor to be broadcast in colour.

"I hadn't really found myself before Doctor Who," he said in an interview with Radio Times magazine back in 1973.

"I was always scared of myself… Doctor Who gets into your blood."

In another RT interview, he described the part as "exciting" and "gutsy", and "one of the most sought-after leading man's roles in television", before then quoting the following line from 1968's The Web of Fear: "There's nothing more frightening and alarming than finding a Yeti or some such creature sitting on the loo in Tooting Bec."

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But, of course, there would be no Third Doctor without his plucky companion Jo, played by Katy Manning, who wore one of his iconic jackets as a tribute to her dear friend while filming miniseries Tales from the TARDIS in 2023.

"It still feels Jon, it almost smells Jon – it's filled with Pertwee!" she said. "I'd nestled under it on so many cold locations.

"Whenever someone has a velvet jacket on now, I get butterflies in my stomach. Velvet hugs!"

Call the Midwife continues Sunday at 8pm on BBC One and iPlayer.

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