Editor’s note: The below recap contains spoilers for Doctor Who Season 1 Episode 3, “Boom.”

The Big Picture

Ncuti Gatwa shines as the Doctor in an emotionally charged episode.
Steven Moffat crafts tense storytelling with war, faith, and capitalism themes.
Millie Gibson delivers a heartfelt performance as the mysterious Ruby Sunday.

Every Doctor Who showrunner, past and present, has their merits, each with their fair share of stand-out episodes. That being said, there’s something undeniably special about a team-up between Russell T Davies and Steven Moffat. Having penned some of the best episodes of Davies’ initial era — from “Blink” to the “Silence in the Library” two-parter — Moffat is back to break hearts and deliver some of the season’s most emotional moments with “Boom.” This week’s installment gradually raises the stakes every ten minutes, pushing the Doctor (Ncuti Gatwa) and Ruby (Millie Gibson) to the brink — and then right over the edge.

During Moffat’s time as showrunner, he had a habit of “killing” the Doctor’s companions. Amy and Rory were taken by the Weeping Angels and made to live out their days in 1940s New York. The Doctor threatened the very fabric of space-time to rescue Clara so she could keep living in the space between heartbeats, and Bill was saved from life as a Cyberman through the power of lesbianism and an alien entity. Now, in the space of just one episode back, Moffat’s managed to do it again with Ruby dying and coming back to life on the battlefield. The episode also introduces a very special guest star, Varada Sethu making her debut as Mundy Flynn. While we’ll have to wait to see how she and the Doctor cross paths again in the future, having her arrive so early opens up the door for a plethora of possibilities.

Doctor Who The show follows the adventures of a Time Lord “The Doctor” who is able to regenerate, and the Doctor’s human friends. The Doctor and companion’s journey through time and space in the TARDIS – a time-traveling ship shaped like a police box – saving the universe with a combination of wit, bravery, and kindness.Release Date March 17, 2006 Seasons 14 Studio BBC America Streaming Service(s) Disney+

Steven Moffat Returns to ‘Doctor Who’ With a Masterclass in Suspense
Opening on a war-torn planet, two soldiers are making their way home through the middle of a mine-laden battlefield. One, a man with temporary blindness, contacts his little girl back at base camp insisting that she brush her teeth. Giving the audience a brief primer on this place and these people, we meet Mundy and Canto, two other soldiers with a blatant “will they, won’t they” thing going on. They’re all members of the Anglican Marines, a group that should be familiar to fans of the Moffat era. While these are all new characters, the Anglican Marines appeared in various episodes in Series 5 and 6, the last of which was “A Good Man Goes to War.” Back on the minefield, trouble arises when the seeing soldier spots an ambulance in the distance. Instead of offering sanctuary, the pair are intent on avoiding the machine, signaling something sinister lurking within.

When the seeing man accidentally trips and falls, he lands on a mine, having mere seconds to react before he’s obliterated on the spot. The ambulance, bearing the face of the mystery woman, then jumps into action after detecting combat, analyzing the blind man with a distinctly harsh wartime lens. The man, John Francis Vater, begs for his life in the face of this unfeeling machine, insisting that he’s only temporarily blind and that he must be allowed to return home as the sole caregiver for his daughter, Splice. None of that matters to the machine, however, as it’s already determined he’s not worth saving. It allows him to send a message to his next of kin and promptly smelts him into a memorial casket the size of an urn, bestowing him with every politician’s standard — and useless — crisis response, “thoughts & prayers.”

Elsewhere, unable to let a call for help go unanswered, the Doctor bounds out of the TARDIS with reckless abandon, wildly seeking out the source of the scream he heard. As he runs through the battlefield, the tension rises until he finds himself stranded on an explosive. Having fallen behind, Ruby wanders out after him. With another nod to music, the Doctor helps Ruby find him — and helps himself enter a “zen state” — by singing the “Skye Boat Song,” widely popularized by Outlander. As Ruby approaches, Moffat doles out exposition while ratcheting up the tension by having the Doctor explain the stakes to Ruby as she assists in identifying the bomb. Gatwa is a tour de force for this entire episode, and it starts right from the jump as he exhibits how genuinely terrified the Doctor is by rambling as a coping mechanism mid-crisis.

He sends Ruby off to search for something that he can use to counterbalance his weight on the bomb. In the midst of some truly biting political commentary, we’re treated to Ruby’s first “I’m on an alien planet moment” as she takes in the marvelous skyline filled with planets and stars. The moment of levity leads right into one of the season’s most powerful scenes yet. While Moffat’s writing was somewhat controversial in his earlier seasons, he’s certainly brought his A-game to “Boom,” infusing the episode with all the best elements featured in Series 8-10 — anti-capitalist commentary, a heart-pounding exploration of grief, and a captivating level of trust between the Doctor and his companion.

While the Doctor insists that Ruby toss him the urn and run, she knows it’s far too risky, insisting on walking all the way to him and handing it off smoothly. The Doctor protests, insisting that worrying about her safety is only going to make it more difficult for him to concentrate on not moving. Gatwa and Gibson’s chemistry is on full display as the Doctor is forced to be vulnerable and Ruby draws upon her love for him and everything he stands for to be brave in the face of death. It’s an incredibly effective moment, showing us how deeply these two characters trust and care for each other in the space of just a few minutes. Tying everything back to music, Ruby decides to hand the urn off to the Doctor on-beat as he sings the “Skye Boat Song” again. It works, but at a cost — the adrenaline drop has ticked the bomb a few inches closer to detonation, leaving them no room for error. To calm himself further, the Doctor brings up another little Moffat-ism, referencing the moon and the President’s wife, an in-joke between Twelve (Peter Capaldi) and Missy (Michelle Gomez). And while we’re looking for clues, the Doctor is technically the president of Earth, and his wife is River Song (Alex Kingston), but more on that later.

‘Doctor Who’ Tackles Faith, Capitalism, and War in “Boom”

Further assessing the situation, the Doctor and Ruby are greeted by an AI of the fallen soldier whose remains just saved the Doctor’s life. When the AI John explains that he was “humanely terminated,” the Doctor further elaborates on the evils of war entwined with the predatory nature of capitalism. In this war-torn future, the Villengard company (a clever name for a malicious security system) is the sole supplier of weapons in every major conflict, maintaining a steady flow of death and cash.

When Splice arrives looking for her father, Ruby and the Doctor must play it cool while their hearts break for her. As Splice accidentally sets off the voice activation on her father’s remains, Moffat ramps up the tension again as the mine threatens to take them all out in a kerfuffle. As if that wasn’t enough, Mundy arrives just in time to put the Doctor in her crosshairs. The Doctor is quick on his feet, breaking the tension with a joke about how she and Ruby should get married so that her name would be Mundy Sunday. Ever the soldier, Mundy delivers some more crucial information for the episode’s unfolding narrative, explaining that the Doctor is a dead man either way, as the bomb has a fail-safe that will detonate if he stands there long enough. With more biting commentary about the Church’s malicious machinations, the Doctor begins to put the pieces of this mystery together, already twelve steps ahead of everyone around him.

Going from terrified to terrifying and back again, the Doctor begs for his life, insisting that it’s not just his life at stake. Because he’s not human, if the bomb does go off it could wipe out half of the planet. To make matters worse, the ambulance bot returns. However, it has trouble analyzing the Doctor and begins to glitch out. Ruby jumps into action, attempting to draw the bot away from the Doctor, acting on pure instinct. Finally beginning to see the severity of the situation, Mundy follows her out and the two hatch a plan for Ruby to safely wound Mundy so that the ambulance will prioritize her over the Doctor. Unfortunately, everything goes sideways when Canto shows up and shoots Ruby in cold blood, assuming she was intent on hurting Mundy. Time slows down as Ruby crashes back into the pit, unable to move. It’s heart-pounding, devastating, and classic Moffat. The Doctor’s heart breaks wide open as Ruby falls to her would-be death and all he can do is stare in horror. There’s no limit to the praise Gatwa deserves for this episode, running a wild and violent gamut of emotions, all while unable to move.

Despite Ruby’s life now being on the line, the ambulance does effectively switch priority to Ruby in the wake of her fall. As it attempts to analyze her, the machine glitches out again when trying to identify her next of kin — possibly indicating that her birth mother is another “complicated space-time event” like the Doctor. While Ruby does appear to be human, it’s entirely possible that she’s been chameleon arc-ed, with her true identity hidden away. If she is a Time Lord too, her mother could be someone like River Song, a child of the TARDIS, the Doctor’s granddaughter, Susan, the Doctor’s daughter, Jenny, or even the Doctor himself, as he has the ability to exist as any gender. Gibson is heartbreaking as she begs the machine to just tell her who her next of kin is before she dies. The snow from “Space Babies” begins to fall again before time stands still in the face of Ruby’s apparent death. To twist the knife, the machine makes it clear that saving her is possible, but refuses to as she’s not a faithful paying customer.

‘Doctor Who’ Follows the Life and Death of Ruby Sunday

Motivated by a strong mix of fear and regret, Mundy now begs the Doctor for the answers, pleading with him to simply tell her what to do. While he wishes to be above war, and maybe now he’s learned enough lessons that he can be, the Doctor is no stranger to soldiers. He tells her to stand down and surrender because the bombs are her bombs. Splitting his attention between Ruby’s lifeless body and Mundy’s crumbling faith, the Doctor breaks down the plot twist in a captivating monologue, explaining that the Anglicans have been fighting themselves this whole time after declaring war on an empty planet.

Unfortunately, in order to surrender, Mundy needs proof, so the Doctor calls upon the parental instincts of the John AI and commands it to find evidence that the planet was always uninhabited. As the tension reaches a fever pitch, it seems as if all hope is lost. Canto is taken out by the ambulance just moments after confessing his feelings for Mundy, the failsafe kicks on, setting a countdown to “boom” from ten, and Ruby shows no signs of coming back to life. But in a very Galaxy Quest “it always stops at one on the show,” moment, the John AI comes through and saves everyone with the power of his love for Splice. All the bombs are neutralized, and the ambulance is forced to bring Ruby back from the dead.

Bounding around now that he can move again, the Doctor rushes to her side, barely giving away how genuinely devastated he would’ve been to lose her. In spite of their losses, the whole ensemble can’t help but be swept up in the Doctor’s joy over ending a war with the power of love. As they say their goodbyes, the Doctor promises to check in, requesting his favorite snack — fish fingers and custard, a nod to the Eleventh Doctor (Matt Smith) — upon his return. Moffat caps off the episode with another signature staple of his writing by promising that, even after death, those we love are never really gone. Quoting “An Arundel Tomb” by Peter Larkin, the Doctor tells a very alive Ruby “What survives of us is love,” leaving her with this crucial lesson: death is inevitable, but if we live fully enough we can leave behind a legacy of love.

New episodes of Doctor Who will air on Disney+ on Fridays at 7 PM ET.

Doctor Who Steven Moffat’s new Doctor Who episode, “Boom,” is a masterclass in tension building.ProsNcuti Gatwa delivers his best performance yet as the Doctor.Millie Gibson grounds the mystery of Ruby Sunday through emotional depth.Varada Sethu makes an impressive debut that offers intrigue about her return. ConsThe end of the conflict is wrapped up quite quickly.

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