The premiere episode of "On Call" kicks off with Officer Maria Delgado patrolling the vibrant streets of Long Beach, California, her keen eyes catching sight of a vehicle with outdated registration tags. Approaching the car, she discovers the driver to be a notorious figure entangled in the web of drug abuse. Inside the vehicle, accompanying him, are another man and a woman, the latter of whom is unconscious, sparking Delgado's suspicion that she might be a minor. A tattooed individual occupying the back seat fills her with further caution.
As she orders them to step out, the tension escalates abruptly when the tattooed man pulls a trigger, wounding Delgado before they flee the scene, leaving her bleeding profusely on the pavement.
The narrative transitions to the Long Beach Police Department, where Officer Alex Diaz, a fresh recruit, stands alongside his colleagues, paying respects to the fallen Officer Delgado through a heartfelt tribute. Lieutenant Bishop arrives, bringing news on the suspects behind Delgado's tragic demise: Eddie Watson, alias Maniac, a feared gang member, and Juan Cortez, the getaway driver. Bishop inquiries whether Harmon, the seasoned officer, is amenable to partnering with a rookie or prefers some solo time to grieve. Harmon, resilient and composed, asserts her readiness to work alongside Diaz.
Together, they embark on their patrols, engaging in lighthearted chatter as Harmon presents Diaz with a tiny, symbolic 'get-out-of-jail-free' card—a traditional token she bestows upon her trainees. Their routine is shortly interrupted by a domestic disturbance call, where a woman has been brutalized by her own son. While other officers apprehend the son, the mother engages in a heated altercation with Harmon, vehemently opposing her son's incarceration.
Harmon proceeds to give the son a piece of her mind, her words sharp and cutting, while Diaz, inadvertently, captures her menacing demeanor on his body camera—a device he ought to have switched off earlier. Harmon reprimands him for this oversight. Subsequently, the mother confines herself in the bathroom, prompting the officers to forcibly break down the door, discovering her in a state of drug-induced euphoria.
Later, as the officers patrol their beat, they encounter a vehicle with an expired license plate. The driver, the owner's brother, presents a valid license but his appearance unmistakably betrays his struggle with drug addiction. Despite no illicit substances being found on him, Harmon orders his release, yet Diaz persists in engaging him, convincing him to seek his father's help for his addiction. Diaz harbors hope for the man's rehabilitation, whereas Harmon remains skeptical.
Over dinner, Harmon instructs Diaz to report her earlier threat against the man who assaulted his mother. Diaz, steadfast in his loyalty, declines, asserting that he is not a informant. Their meal is interrupted by a call regarding a green car with Eddie Watson sighted nearby. The officers swiftly locate and pursue the vehicle, which ultimately veers off the road and crashes. Harmon trains her gun on one of the occupants, but Watson flees the scene. Despite her commands for Diaz to stand down, he pursues Watson, ultimately losing him and earning a stern rebuke from Harmon for disobedience. She suspects his disregard for her orders stems from a conversation with Sergeant Lasman, a figure with whom Harmon shares a frosty relationship. Diaz clarifies that Lasman merely mentioned Delgado, Harmon's former trainee, and her profound grief over her demise. Harmon's reaction reveals lingering guilt over the incident.
Diaz attempts to return the 'get-out-of-jail-free' favor Harmon once granted him, but she declines, insisting he may need it in the future. With this exchange, they resume their patrol duties, marking the conclusion of On Call Episode 1.
