BBC's Ghosts - Why Mary’s shock exit had to happen

Just minutes into the poignantly titled Gone Gone, witch trial victim Mary (brilliantly played by Katy Wix) was suddenly bathed in golden light before ascending into the afterlife. Her last word was a heartbreaking "Ooh" as she gently floated up through the ceiling.

The other Button House ghosts were left open-mouthed and it wasn't long before they found themselves in a tailspin. Scoutmaster Pat (Jim Howick) comforted naive noblewoman Kitty (Lolly Adefope); trouser-less Tory MP Julian (Simon Farnaby) saw red; army officer The Captain (Ben Willbond) kept busy to avoid thinking about it; romantic poet Thomas (Mathew Baynton) made it all about him, as usual; even the stiff upper lip of Lady Fanny (Martha Howe-Douglas) wobbled.

It seems that's the last we've seen of Mary, who has become a firm favourite of Ghosts fans. She was the 17th century West Country peasant woman who added comic relief every time she pluralised random words ("I smells burnings"). She was deeply superstitious about wedding garters and lucky cake-throwing. She called TV cameras "one-eyed metal cows", cocktails "the devil's juice" and swans "Lucifer's lackeys".

Way back in the Stuart era, Mary was cynically blamed by male villagers for a poor harvest, falsely accused of witchcraft and burnt at the stake. As a result, her face was forever smeared with soot and she constantly smouldered. The living could smell toast if she passed through them. "She's at peace now," Pat reassured the tearful Kitty.

The masterminds behind the show - the Horrible Histories gang of Baynton, Howe-Douglas, Farnaby, Howick, Willbond and Laurence Rickard - told RadioTimes.com: "We were so lucky to have Katy Wix with us in Button House for four fun-filled series. She, ironically, breathed life into the role of Mary, as only Katy could, making her into such a unique, hilarious and popular character. We're sad to see her go but can't wait to see what she does next."

Why did she become the first main character to move on? It might well have been a workload issue for Wix. She's increasingly in demand – her CV includes Carole in Stath Lets Flats, Fergie in The Windsors and Jules in Big Boys. She has a flourishing writing career, having published acclaimed memoir Delicacy last year, and she's currently co-writing Fat Camp, a comedy series about a children's weight loss retreat, in which she'll also star.

While this is the end of the road for Mary, there's plenty more to come from Wix.

Viewers will miss Mary too, but at least she was given a worthy send-off.

Despite its supernatural silliness and high gag rate, Ghosts is frequently unexpectedly affecting – see the episodes about Thomas's death in a duel, Fanny's murder at the hands of her husband, or The Captain's unrequited love for his wartime lieutenant. This was definitely one of those bittersweet moments. In fact, Mary's departure was the most moving storyline yet.

Her character allowed the writing team to subtly explore themes of sexism and misogyny. Because of Mary's horrific death, she was painfully shy and traumatised. Two episodes ago, she finally plucked up the courage to tell her story. We saw how she was unjustly executed and belatedly learned to speak her mind with the help of her feisty undead friend, Puritan housemaid Annie (Bridget Christie). "Now we're free," Annie told her. "More than we ever were in life."

When Annie moved on herself, Mary watched her go with mixed feelings, muttering: "Lucky cow." Indeed, the show has been slyly laying the groundwork for Mary's own exit all series. When her fellow ghosts briefly feared that caveman Robin (Rickard) had passed over first, Mary said: "He’s been sucked off, the lucky beggar."

Now it was Mary's turn in a gasp-inducing, tear-jerking plot twist. After realising that her spirit friends were struggling to process their loss, landlady Alison (Charlotte Ritchie) decided to hold a memorial service. As she explained: "It's not the end of her life but it is the end of her afterlife."

Alison and Thomas gathered items to help them remember her: the sketched portrait of Mary, a bulb of fennel (her favourite vegetable, like a fancy onion), a magazine with her beloved "Loose Womens" on the cover, a framed photo of Alison's husband Mike (Kiell Smith-Bynoe), on whom Mary had a not-so-secret crush. Alison put it all in a wicker basket "five potatoes high", as Mary insisted baskets should be, and buried it beneath her favourite tree.

There wasn't a dry eye in Button House. Well, until their minute's silent contemplation was interrupted by the strains of Black Lace and Gangnam Style drifting in from the children's birthday party indoors. The ghosts promptly hit the dance floor because "Mary would have wanted us to have fun". For a show about dead people, Ghosts is joyously life-affirming.

As two of the oldest ghosts Mary and Robin had spent centuries together and grown so close, there were once hints of potential romance. Hence it felt strange that Robin initially seemed unaffected by her departure. He later admitted that he has his own way of mourning the many deaths he's witnessed. "Find them a star," he growled, gazing up at the night sky. "Because that's where we go, back to the stars. That one has a twinkle. Goodbye, Mary."

Mary's appearances in Ghosts were quietly diminishing. She was sometimes absent from ensemble scenes. It began to look suspiciously like Wix was unavailable for filming due to scheduling conflicts.

Last week's episode saw Mary wandering the grounds alone, chatting cheerfully to herself while the rest of the ghosts tried to apologise to Alison for their bad behaviour. Mary had done nothing wrong, so rightly refused to join them. Death had given her a voice at last. "I hope whatever comes next is even better," she said.

We hope so too. RIP.

Ghosts is available to stream on BBC iPlayer. Check out more of our Comedy coverage or visit our TV Guide to see what's on tonight.

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