Episode 1 of *Tempest* opens with Seo Mun-ju recounting a haunting dream: she, the wife of politician Jang Jun-ik, is shot. The scene then shifts to Jun-ik, who abruptly awakens from his sleep, while Mun-ju is out for her morning run. News reports fill the airwaves, detailing the escalating tensions between North Korea and the United States, led by the resolute President Hauser.
As Mun-ju runs, she skillfully evades the security detail tasked with tailing her, despite their instructions to keep her in sight. Upon her return, she engages in a heated argument with Jun-ik about their presence. She describes her morning runs as a sacred form of prayer, a time when she craves solitude. Jun-ik, however, is consumed by worry for her safety and stands firm in his refusal to grant her that privacy.
We soon discover that Mun-ju was once a distinguished UN ambassador, stationed abroad, before suddenly resigning and returning home. Jun-ik, a prominent figure in the New Republican Party, is the leading contender to challenge the incumbent South Korean President, Chae Kyung-sin, in the upcoming election.
Mun-ju attends a political gathering where she crosses paths with President Chae. Their conversation reveals a decade-long working relationship, now strained by the prospect of Jun-ik running against the president. Mun-ju informs President Chae of her intention to step down and mentions that Jun-ik wishes to speak with her later that evening.
Subsequently, Mun-ju reconnects with Yeo Mi-ji, her personal aide and longtime confidante. Mun-ju expresses regret for having to cancel their plans for the night, explaining that Jun-ik must attend a mass prayer event. Back at home, Jun-ik presents Mun-ju with a cross necklace. Memories flood back as she recalls the urgency in his voice when he requested her return to South Korea. She inquires about the reason for his concern, and he vows to reveal all later that night.
The couple then makes their way to a church, which is hosting a mass prayer for the peaceful reunification of the two Koreas. Outside, a group of protestors voice their vehement opposition to reunification, their anger intensified by Jun-ik's presence—a man who once stood against the very cause he now supports. As they enter the church, Mun-ju's gaze falls upon a cameraman positioned in the balcony area, capturing every moment. Jun-ik instructs his security personnel to remain outside and arranges for a secure location for Mun-ju to retreat to after the mass concludes.
After Jun-ik delivers a brief speech, a man clad in military attire abruptly rises and shoots Jun-ik, accusing him of treachery. Mun-ju springs into action, attempting to shield Jun-ik amidst the ensuing chaos. In a twist of fate, the cameraman from earlier tackles the soldier to the ground. Alas, Jun-ik soon succumbs to his wounds and loses consciousness. Witnessing this, the soldier swallows a pill, meeting his demise within seconds. Jun-ik is hurriedly taken to the hospital, but it is too late—he has already passed away.
Following the funeral, Mun-ju shares a meal with Jun-ik’s family, which includes his brother Jang Jun-sang, his mother Lim Ok-seon, and his grandmother. The grandmother voices her sorrow, lamenting that the family now bears the burden of three widows, as her husband and son had also departed before. It becomes evident that neither the grandmother nor Ok-seon hold Mun-ju in high regard.
Jun-sang attempts to shift the mood by mentioning that the political party is considering endorsing him as Jun-ik’s successor. However, Ok-seon expresses doubts about his capability. Instead, she proposes that Mun-ju should vie for the presidency.
A lawyer arrives bearing Jun-ik’s will. It bequeaths everything, including the family’s wealth, to Mun-ju. This revelation incites fury in Ok-seon and Jun-ik’s grandmother, who vow to challenge the will in court.
Meanwhile, it is revealed that the cameraman from the church possesses Mun-ju’s necklace. An American named Ethan contacts him, addressing him as Mark, and informs him that a client has requested his services for a job. The assignment is to monitor and safeguard Mun-ju without her knowledge. It turns out that he has already been keeping a watchful eye on her and declines Ethan’s offer.
During a meeting with the police, Mun-ju learns the identity of the killer: Sergeant Kim Yong-ju. She also discovers information about Mark, whose real name is Baek San-ho, though the police have been unable to locate him for a witness statement. Mun-ju arranges a meeting with the church’s priest and requests him to inform San-ho that she is seeking him out.
San-ho encounters Mun-ju during one of her jogs and returns her necklace. He swiftly realizes that she is being followed by a car. When the men in the vehicle attempt to intercept them, San-ho swiftly subdues them all and guides her into the mountains, where an even larger contingent of men is searching for her.
When they finally secure a moment of privacy to converse, Mun-ju turns to him, her voice tinged with urgency, and inquires whether he caught Sergeant Kim's haunting last words before he breathed his last: "I killed the spy." San-ho nods, his expression grave, and reveals that he harbors suspicions of a hidden hand orchestrating events from the shadows.
He pulls out his phone, displaying a video captured within the hallowed halls of the church. The footage captures Sergeant Kim stealthily concealing a piece of paper within the pages of a Bible. San-ho recounts how he managed to retrieve the paper, only to discover a phone number scribbled on it—a number that, upon investigation, left no trace in any existing records, as if it had never been.
To further paint the picture, he presents another clip showing Sergeant Kim in a clandestine meeting with Jun-sang. Meanwhile, on a nearby street, Jun-sang sits patiently in his car, his men scouring the area in a frantic search for Mun-ju.
