'Sister Boniface Mysteries' Season 4 Opens with a "Biff! Pow! Zap!"

A spin-off of the beloved Father Brown series, Sister Boniface Mysteries, with Lorna Watson reprising her role as the titular brainy crime-solving nun, combines mystery, humor, and a nostalgia for the swinging sixties. Set in the Cotswolds in the picturesque village of Great Slaughter, this cozy crime favorite opens Season 4 directly following the events of the Christmas episode, which aired in December 2024. 

(*Don’t get too excited about the place name – it derives from the Old English slōhtre, meaning "muddy or wet place," and has nothing to do with the series’ body count.)

So it’s a bit of a surprise to find the Season 4 return, "Biff! Pow! Zap!" opening in the lair of superhero Foxman – real name Walt Nort (Dan Skinner) – and his sidekick, Beaver, real name Brett Hyde (Nathan McMullen). The two are planning their next mission to jolly old England, where they will protect the legendary Darlington Ruby. As they zoom off into the superhero stratosphere, a film production truck drives up to the stately pile of Great Slaughter’s aristocratic landowner, Lord Matthew Sedgewick (Sam Alexander). 

Director Hank Sawyer (David Bedella), sporting an eye-watering tan and a shaky American accent, emerges from the house to meet today's visitors to the set, the enthusiastic young reporter from the Albion Bugle, Norman Walley (Jack Gouldbourne), who's brought along hunky DI Sam Gillespie (Max Brown), DS Felix Livingstone (Jerry Iwu), and Constable Peggy Button (Ami Metcalf). Peggy is particularly starstruck and is thrilled to pose for a photograph with superhero actors North and Hyde, whose off-screen relationship is barely civil. 

A bright red moped is the next to arrive, driven by Sister Boniface with Reverend Mother Adrian (Carolyn Pickles) in the sidecar, complaining all the way. They are here to see Lord Sedgewick on serious convent business, as the rest are directed to catering, where Mrs. Clam (Belinda Lang) and Miss Thimble (Sarah Crowden) are serving up homemade delicacies, such as Fox Blancmange with Ham. Hank flirts with Miss Thimble, asking if her Fox Cake has any fox in it. But everyone, particularly DI Gillespie, is struck dumb at the arrival of the episode’s star, the glamorous Camilla Cattermole (Elisabeth Dermot Walsh). 

In her own words, she is an “icon ... glamour puss ... goddess of the silver screen...” (Although all those who've worked with her might choose other epithets). She’s accompanied by her loyal sister Jane (Anna Blackburn), her downtrodden drone and general dogsbody. Camilla checks out the male talent present and zooms in on Sam Gillespie, throwing her fur coat at her sister and leaving her to deal with the spilled luggage. Gillespie helps Jane pick up and repack their belongings as Sister Boniface and the Reverend Mother look on with distaste. 

Hank gives the order to shoot a scene in which Camilla learns from Foxman and Beaver (wearing regular clothes) that a notorious villainess known as the Minx is planning to steal the Darlington Ruby. She and Foxman express an irresistible attraction to each other, only for Camilla to burst out laughing and ruin the take. At this point, the Reverend Mother has had enough. She’s just learned from Sedgewick that even though he’s lending his house to the TV crew, he is in financial difficulties and may not be able to provide the funds to repair St. Vincent’s, which is rapidly falling apart. She cannot tolerate Camilla’s behavior and speaks sternly to her, after which the cast and crew applaud. Camilla walks out.

Gillespie checks in on Jane, who admits she has an escape plan, taking acting lessons... Naturally, Camilla then flounces in to apologize to her sister, make a pass at Gillespie, and flounce out again. Her latest disruption is to perform her own stunt in the next scene, dressed in her Minx costume and mask, as she descends from a window on a rope. But tragedy strikes when the rope breaks and Camilla falls to her death. Jane is heartbroken, admitting she told Camilla about her acting lessons, and that’s when Camilla decided to do the stunt herself. She loved her sister, explaining that Camilla had been damaged after being manipulated by their mother into becoming an actor and denied a normal childhood.

Sawyer is now in deep trouble. The episode is only partially shot, the insurance won’t pay for any losses, and the studio won’t cover any more shooting. The show is over, and so is his career. At this point, Mrs. Clam, wielding an enormous teapot, suggests that they shoot more episodes, but it can’t be done, because the animosity between North and Hyde has reached a breaking point. North will sign no more contracts, and without Foxman, the show cannot legally continue.

Sister Boniface is in her laboratory, running tests as water cascades down from holes in the roof. Peggy brings in an important clue: a sample of an unknown substance from the sofa, wrapped in a letter containing a written warning to Camilla from Hank. Under questioning, he admits he wanted Camilla out; he’d had enough. But he insists he didn’t kill her. He allowed her to do the stunt since it was the only way he could complete the episode and qualify the series for syndication. Sister Boniface suggests he ask Jane to assume her sister’s role since they look so similar. 

(Spoiler alert, almost: You know where this is going, don't you? As "Jane's" appearance and even personality begin to change, it's clear this isn't just the shy wallflower coming into her own but something far more deadly. Sit back and enjoy!)

Jane is resistant at first, but Hank’s persuasion, Sister Boniface’s gentle sympathy, and Gillespie’s offer to act as her personal bodyguard persuade her to film just the one scene necessary to provide a coherent storyline. The scene is a triumph, but as Foxman leaves the set, he admits to Gillespie and Sister Boniface that Camilla was threatening to blackmail him because he wore a very discreet corset. 

Gillespie, falling for Jane, helps her rehearse her lines, and they share a tender kiss, which is interrupted by Peggy with the news that Sister Boniface has made a breakthrough in the lab. (He claims he is supporting a grieving woman when the good Sister points out the lipstick on his face.) Sister Boniface found some footage taken from outside the building showing who was in the room before the stunt took place, and Gillespie recognizes Lord Sedgewick. But when he's questioned, Sedgewick confessed he was afraid Camilla would break yet another of his valuable items, now irreplaceable since he’d let his insurance lapse.

Jane admits to Gillespie that she doesn’t want to be alone at night. (Isn’t it interesting how she becomes more like her sister as time passes?) Naturally, she seduces him. (The minx! He's quite happy about it too.) The next day is the last day of filming, but disaster strikes when Jane finds Gillespie unconscious outside her bedroom and is rushed to the hospital. Upon arriving, Jane informs Sister Bonifant and DS Livingstone that the reason Gillespie was outside her room was due to pursuing someone who had been attempting to break into the bedroom.

Back in her leaky laboratory, Sister Boniface runs an analysis of the sticky substance found on Camilla’s written warning and on the weapon used on Gillespie. It’s bubblegum, and there’s only one member of the team who chews it: Beaver, aka Brett Hyde. He admits he and Camilla were lovers, an affair that lasted until the day before, when she moved on to Gillespie. But it’s inadequate proof of murder. Sister Boniface visits Gillespie soon after. He’s not improving. Sister Boniface needs him; he’s her best friend. 

Sam Gillespie remains unconscious, and Jane – actually Camilla, as you've probably guessed – is desperate to get rid of him before he wakes and reveals her crime. She made a terrible mistake the previous night when he caught her smoking and became suspicious because Jane had asthma and didn't smoke. Things were going so well! She'd disposed of annoying Jane after her sister had taken a call from Camilla's agent and found her career was on the rocks. 

Her plans to rise from the ashes as a young, new superstar, Jane Cattermole, were in grave danger now that Gillespie was on his way to solving the mystery. Camilla barricades herself in Sam's hospital room while Sister Boniface, DS Felix Livingstone, and Constable Peggy Button beg her to reconsider. Where's a superhero when you need one?

Right here! Beaver and Foxman dive through the window and save Gillespie just as Camilla is about to smother him with a pillow, while Livingstone arrests Camilla. The superheroes have just finished filming and have yet another quest to fulfill, rescuing Miss Thimble, who stood in for the role of Lady Darlington, the owner ot the priceless ruby, and has since been barricaded in the library behind a secret panel. (We don't know how or why, but I think they just forgot about her.) But when Gillespie groggily asks how the story ends, these two particular heroes find reconciliation and the beginning of a wonderful friendship.

Sister Boniface Mysteries Season 4 continues with new episodes every week on Tuesdays on BritBox through the end of September. Seasons 1 through 3 are currently streaming on BritBox. Seasons 1 and 2 are also available on select PBS Passports for members to stream; check your local service.