Doctor Who Season 1, Episode 3 Recap With Spoilers: “Boom”

A new episode of Doctor Who, starring Ncuti Gatwa as the Doctor and MIllie Gibson as Ruby Sunday, debuted tonight on Disney+. Former Doctor Who showrunner Steven Moffat returns to write the new season’s third episode, “Boom.” We’re here with the recap of the latest episode of Doctor Who, Season 1, Episode 3, “Boom.”

SPOILERS follow for Doctor Who Season 1, Episode 2, “The Devil’s Chord.” Recap begins now:

Two soldiers slowly make their way through a battlefield. One wearing a blindfold, John Francis Vater (Joe Anderson), uses his comm to call his daughter, Splice (Caoilinn Springall). The other soldier, Carson (Majid Mehdizadeh-Valoujerdy), seems concerned that an ambulance is nearby. At a camp, another soldier named Monday Flynn (Varada Sethu, who is set to join Doctor Who as a new companion next season) convinces soldier Canterbury “Canto” Olliphant (Bhav Joshi), to switch watch with her.

Back on the battlefield, Carson sees an ambulance and backs away. He steps on a mine and is destroyed. The mine triggering attracts the ambulance, which attaches to and scans Vater. She determines his temporary blindness does not meet the threshold to be worth treating. Vater records a message for his daughter before the ambulance kills him.

The Doctor (Ncuti Gatwa) hears Vater’s scream from within the TARDIS. He goes rushing off to investigate and ends up stepping on a landmine before he sees it. Ruby (Mille Gibson) searches for the Doctor and finds him standing on the mine and singing to keep his vitals steady, trying not to trigger the mine any further. The Doctor tells Ruby that they’re in the middle of a war and explains that he can’t move from the mine, which has glowing green lights, or he might trigger it. The lights still aren’t fully triggered.

Ruby goes to investigate the scream the Doctor heard. After gazing at the unfamiliar sky of her first alien planet, she discovers an object shaped like a canister. The Doctor tells her it is a “casket,” which is the remains of a person. The Doctor wants her to toss it to him so he can use its weight to shift his position without triggering the mine, but Ruby insists on getting close enough to hand it to him, despite the danger. The time the handoff with a song and the lights progress due to the Doctor’s increased adrenaline but the mine does not go off.

The Doctor reads John Francis Vater’s name off of the “casket,” and it triggers a holographic AI reconstruction of the soldier who explains what happened to him. The Doctor explains that the ambulance and the weapons are sold by the Villengard Corporation, who have an algorithm designed to maximize profits by keeping just enough casualties to keep the war going.

Splice finds them after hearing her father’s voice. She tells them about how her mother was “gathered up by God.” Splice tells them her name, which triggers the hologram again, and Splice rushes toward them. Ruby has to tackle her to stop her from knocking the Doctor off the mine.

Monday finds them and puts the Doctor at gunpoint. She tells them they’re fighting a war against an enemy they’ve never seen and demands he drop the casket in his hand. She’s an Anglican marine, the church, and military having become one in humanity’s future. The Doctor tries to explain that he’s a Time Lord, but Monday begins firing at his hand to get him to drop the casket, telling him he can’t escape the mine, and that it’s on a timer. He warns her that the energy inside of him will cause a huge explosion if the mine kills him. She scans him and determines that he could destroy half the planet.

The shots attract the attention of an ambulance that attaches to the Doctor. Monday tells Ruby to shoot her arm to draw the ambulance away. As Ruby is aiming, Canto arrives and assumes that Ruby is attacking Monday. He shoots Ruby, and Ruby hits the ground. The ambulance asks for her next of kin, and it begins to snow and time slows. The ambulance withholds treatment because Ruby isn’t part of the Anglican military.

The Doctor tells Monday she needs to surrender the war to stop the mine. He tells her there’s no enemy on this planet. When the Anglicans declared war, they activated the Villengard algorithm. They’ve been fighting their hardware ever since. Monday demands proof, so the Doctor orders the Vater AI to infiltrate the ambulance’s system and find the evidence. The AI takes some convincing, but the Doctor speaks to it “dad to dad” and it makes the attempt.

Monday and Canto discuss their feelings for each other while Canto tries to hack into the ambulance. He gets distracted and the ambulance shocks him, killing him and creating another AI where he was. The AI confesses Canto’s feelings for Monday to her.

The Doctor realizes the algorithm is fighting back against their attempts to stop it. The mine seems poised to go off but as the countdown ends, Vater’s AI takes over the ambulance’s programming. It prevents the explosion and revives Ruby. The AI took down the whole Villengard mainframe.

Ruby, the Doctor, Monday, and Splice enjoy the alien landscape for two minutes before the Doctor is ready to move on. The Doctor says he’s sorry about Splice’s dad, but she’s unphased, insisting he’s dead but not gone. The Doctor tells Splice and Monday that he’ll be popping in again. The Doctor and Ruby reflect on death briefly before returning to the TARDIS.

New episodes of Doctor Who debut on Fridays exclusively on Disney+.