The fourth episode of Season 4 of "9-1-1: Lone Star" kicks off with a jarring scene as Carlos awakens to the melodious yet eerie tune of a woman cheerfully preparing breakfast, her actions starkly contrasting with his predicament. His limbs bound and helpless, he's informed by this enigmatic figure that she was the one who dealt him a brutal blow with a shovel. Adding to the intrigue, she casually mentions TK's incessant calls and how she'd silenced them by dismantling his phone.
Carlos's eyes widen in horror as he catches sight of a concealed corpse within the kitchen's shadowy recesses, but the woman protests innocence, claiming the girl's demise a tragic mishap. Despite his pleas for mercy, she coldly informs him that her son will soon return home, eager to make Carlos's acquaintance.
Meanwhile, Owen finds himself embroiled in a high-stakes encounter with the FBI, summoned by O'Brien's cryptic message. Casey, determined to uncover the truth, insists Owen wear a hidden microphone to record their conversation. She harbors a glimmer of hope that O'Brien's intentions have shifted, that he's ready to confess and expose the Honor Dogs' nefarious operations. Owen, however, senses a sinister motive behind the secluded meeting spot, fearing O'Brien's ultimate goal is his own elimination. Casey's quip about turning a murder attempt into a strategic advantage only serves to heighten the tension.
As they strategize, Owen's phone rings, disrupting the tense atmosphere. It's TK, desperate for guidance. Worried that Carlos harbors resentment, TK seeks his father's advice on whether to wait or confront him directly. Owen counsels patience, urging TK to give Carlos space.
But TK's anxiety escalates when Carlos remains unresponsive, his silence uncharacteristic even in anger. Marjan echoes his concerns, sensing that something is amiss. Nancy's call to the hospital reveals that Iris spent the night alone, Carlos having vanished sometime after 10 PM. This revelation fuels TK's fears, prompting him to enlist Grace's help in tracking Carlos's phone. Grace's subsequent revelation—that the phone is either dead or broken, its last signal emanating from the vicinity of Iris's former captor's lair—sends TK and his Texas Ranger father racing towards the house, hearts pounding with a mix of dread and determination to uncover the truth.
In the interim, Carlos' path crosses with Darryl, the offspring of the woman who had once confined him within the confines of her kitchen. Their mother-son bond is curiously twisted, as she shields her son's nefarious deeds, even amidst the knowledge that he is a serial killer. Darryl, with a sinister plan, requests morphine to eliminate Carlos, but their stash proves scarce. Reluctantly, he dispenses the last remnants to Carlos before hurrying to seal the subterranean entrance. Subsequently, he abandons Carlos's vehicle and stealthily makes his way to the pharmacy where he holds sway, intent on procuring more morphine.
Meanwhile, Darryl's mother keeps watch over Carlos, offering a chilling disclaimer: her actions are devoid of personal malice, merely a mother's desperate attempt to shield her son. She cites a tragic accident from his youth as the catalyst that transformed him into a monster. TK and Carlos's father, Gabriel, join forces, reaching out to the detective assigned to Iris's case. TK uncovers a vital clue—an ID belonging to a homeless woman Iris had sought to aid before her abduction. Their investigation widens, with TK even engaging with Darryl's mother, unaware that Carlos hides within her abode.
The detective's probe deepens, painting a grim picture: Iris and the woman were likely victims of a serial predator who preys on homeless females struggling with mental health issues. TK's heart sinks with dread, yet Gabriel urges him to cling to hope. TK's keen observation reveals a common thread—all the women frequented the same pharmacy for their medications. Following this lead, Gabriel and TK uncover a shocking revelation: Darryl, the pharmacist, had dispensed prescriptions for each of the missing ladies, and his residence stands across from where Iris was discovered.
Elsewhere, TK's efforts to reach his father, who grapples with a personal crisis, prove futile. Owen's rendezvous with O'Brien turns out to be a treacherous ambush orchestrated by Red and his Honor Dogs cronies. Red harbors suspicion, believing O'Brien and Owen to be FBI informants. Owen's realization that he had misjudged O'Brien—a founder who had long abandoned the group, returning solely to investigate his nephew's disappearance—is met with Red's stony silence. Red's refusal to divulge Andy's fate incites a near-brawl between O'Brien and himself. Ultimately, Owen's confession as the informant earns him expulsion from the group, and the FBI shuns both him and O'Brien, leaving them adrift.
As Gabriel and TK unravel the mystery, uncovering the suspect's true identity, Carlos's desperate cries for assistance go unheard amidst the oblivious police presence outside. Darryl's mother, brandishing a knife, looms menacingly, forcing Carlos to devise an alternate strategy. With cunning words, he persuades her to release him, but fate deals a cruel blow as Darryl returns before his escape can be consummated. A fierce struggle ensues, with Carlos gaining the upper hand just as hope seems to dawn. Suddenly, Darryl's mother's resolve shifts, plunging an entire vial of morphine into Carlos's veins.
At the eleventh hour, TK and Gabriel burst in, their timely arrival a beacon of salvation, rescuing Carlos from the brink of despair. Grateful beyond words, Carlos expresses his profound thanks to TK for his life-saving intervention, and together, they speed towards the hospital, their bond forged in the heat of adversity.
The episode culminates in a chilling image: a hooded figure, shrouded in mystery, meticulously crafting a bomb. The telltale signs suggest he is the elusive mastermind behind the ammonium nitrate relocation, his sinister intentions apparent—Owen and the 126 are squarely in his crosshairs. The stage is set for a treacherous confrontation, leaving viewers on the edge of their seats, anticipating the explosive aftermath.
