As one might have guessed, it was the Gobblers who grabbed Lyra in the dark alley last week. They literally put her in a net, hid her in the back of a cargo van and drove her away to their new hidey-hole for stolen children, clearly not knowing who she was. Fortunately, the Gyptians who have been searching for Billy are lying in wait for Gobblers at this location and overcome Lyra’s captors. Before she’s even seen the faces of the men who grabbed her, the van door opens to reveal her savior, Tony Costa (Daniel Frogson).
The Gyptians take Lyra into their community, hiding her on Ma Costa’s (Anne-Marie Duff) boat. They give her practical Gyptian clothes to help disguise her and summon her before their king, John Faa (Lucian Msamati). He tells her that he wants her to stay with them, but that she can go if she wants to. Largely because Pantalaimon (voice of Kit Connor) trusts Ma Costa, she decides to stay and hide with the Gyptians.
The Magisterium has eyes everywhere, though. When desperate Mrs. Coulter (Ruth Wilson) fails to find Lyra in a search of Jordan College, wherein she shows excessive disdain for The Master’s (Clarke Peters) precious scholastic sanctuary (and learns from him that Lyra has the alethiometer), the Magisterium supplies the rumor that the girl is with the Gyptians.
Shortly thereafter, Magisterium police raid the Gyptian boats searching for Lyra. Ma Costa hides her successfully, but the raid convinces Lyra that not only isn’t she safe with the Gyptians, she is also putting them at risk by staying with them.
Lyra storms away, and Ma Costa follows, pleading with her to return. Lyra shouts that she can’t trust Ma Costa when it’s clear that nobody is being honest with her. Ma Costa decides to tell Lyra what she knows, which is that Lord Asriel (James McAvoy) is her father, and that (BUM BUM BUM!!!) Mrs. Coulter is her mother.
Asriel and Mrs. Coulter had an affair that resulted in a baby, Lyra, who looked too much like her true father to pass as Mrs. Coulter’s legitimate child. The scandal led to a confrontation at Lord Asriel’s home with the cuckolded husband and the death of Mr. Coulter. The law wasn’t sure how to handle the situation, so Asriel was stripped of his lands and wealth and Mrs. Coulter lived for years as a pariah. Although Asriel tried to hide Lyra with a Gyptian nurse, Ma Costa, the baby was put in a nunnery. That’s where Asriel stole her before delivering her to Jordan College for safekeeping. Although it’s obvious there’s more to the story, this is as much as Ma Costa claims to know, and her sincerity wins Lyra’s return.
John Faa calls all of the Gyptians together to tell them that they will be traveling North to rescue the stolen children. Not all of his people are willing, scared about challenging the Magisterium by harboring a fugitive, but Lyra gives a speech about Mrs. Coulter’s single-mindedness that stirs them to action.
Before the Gyptians leave London, Tony Costa and Benjamin De Ruyter (Simon Manyonda) sneak out to infiltrate Mrs. Coulter’s home for more information. Lyra sees Tony leaving and gives him a tip about where to look for the goods. While they’re away, Lyra accidentally unlocks part of the secret of the alethiometer by staring at it with a blank mind.
The boys’ excursion to Mrs. Coulter’s is doomed from the start. They get inside successfully, but the ominous sound of something moving in the walls accompanies them as they sneak into her study. Tony digs through the drawer Lyra indicated, coming away with just one document before Mrs. Coulter’s dæmon springs forth from the vent to attack them. Tony and his dæmon escape through a window, but Benjamin and his dæmon get caught (and shot) in the hallway by Mrs. Coulter. She tries to beat information out of Benjamin, but he throws himself down the elevator shaft rather than betray his family, and his dæmon evaporates when he dies.
When Ma Costa discovers Tony’s bed empty, she raises the alarm in the Gyptian community. Lyra seems to keep the secret of where they’ve gone, but she can’t stand to keep one other secret anymore. She decides she can trust Farder Coram (James Cosmo; Jeor Mormont) and shows him her alethiometer. He tells her that the user can move three of the hands to symbols whose meanings correspond with a question, and that the fourth needle then moves independently to indicate an answer. He also tells her that nobody can read alethiometers without studying books about them for years.
Lyra, undeterred, decides that this thing is her only possible chance of helping the boys and uses the three question needles to ask about Benjamin, a spy. She clears her mind, and the fourth needle swings wildly until it settles on a symbol that clearly indicates death: an hourglass with a skull on top.
Eager to let the grownups know what she’s learned, she leaves the shelter of Ma Costa’s boat to find Farder Coram. She tells him she figured out the alethiometer and that Benjamin is dead. At the same time, two enchanted mechanical beetles arrive, “spy flies” that Mrs. Coulter charmed to find Lyra. Farder Coram captures one, but the other flies away to its mistress.
Moments later, Tony returns alone and shares the document he secured on his mission: a list of all the missing children, including Billy. The Gyptians board a large ship, taking Lyra and Pan with them, and head North. And Mrs. Coulter now knows that that’s what’s happening.
Meanwhile, Carlo Boreal (Ariyon Bakare) returns to our world to ask his flunky, Thomas (Robert Emms), what he’s learned about the missing adventurer. The surprising answer is that the man is not from Carlo’s world originally, but from ours. He disappeared more than a decade earlier, leaving behind a wife and child, and his last known location was in Alaska. Thomas ferrets out that Carlo is alone in his pursuit of this man. Carlo engages another flunky to watch the man’s family and report to him.