The opening of Tempest Episode 6 echoes with Frank Sinatra's Christmas tune on the radio, a melancholic signal to Mun-ju and San-ho that the war's imminent onset looms. Mun-ju wallows in her inability to halt the impending conflict, and amidst their passionate embrace, San-ho whispers his disdain for the war, dreaming of a getaway with her to a new life. Mun-ju, caught in the same dreamy reverie, agrees. Later, he proposes they flee to the Gobi Desert, where he finds solace in the unwavering North Star as his only companion.
Meanwhile, in the US, government officials frown upon a news clip of North Korea launching a nuclear submarine. However, the model on display seems vastly different from the one they had been studying, with an expert dismissing its functionality outright. North Korea, in a bold display of defiance, shoots down a US plane that trespassed its territory and issues a chilling warning. President Chae receives a call from the US officials, who implore her to keep an eye on Mun-ju but refrain from retaliation for now. She addresses the nation in a reassuring press conference, urging them to resume their daily lives. Post the conference, Director Yoo unveils his plan to bring Mun-ju down.
In the hospital, Chang-hee wakes up to a newfound realization – he and Mi-ji call Mun-ju to share a chilling discovery: an anonymous telegram account messaging Jun-ik on his secret phone. The chat unveils a video from North Korea's founding ceremony, where an award is bestowed upon...Jang Jun-ik. He was a spy all along! Chang-hee is stunned by this revelation and had set up a meeting with the anonymous sender when his accident occurred.
San-ho now harbors a belief that Kang Han-na is Stella Young, the arms lobbyist who procured materials for the submarine. Moreover, the telegram account ID number matches the one San-ho and Mun-ju saw on the card in Jun-ik's possession. Meanwhile, Han-na has taken up residence in Jun-ik's house, unaware that Jun-ik was also born out of wedlock and never knew Ok-seon as his biological mother. Han-na divulges this truth, having been told by Jun-ik's grandmother.
As San-ho urges Mun-ju to focus on safety and leave their past behind, Mi-ji makes an urgent call – their safehouse is bugged. A news channel has aired a recording of their previous conversation, where they discussed fleeing together.
San-ho's frustration mounted as he searched the house in vain for the bug that had been planted. His agitation reached a peak when he turned to Mun-ju, suggesting they escape on a ship bound for Mongolia. Upon receiving a notification about such a vessel, a chill of realization ran down his spine – someone was indeed watching. With a bag packed and a promise to be back soon, San-ho left, leaving Mun-ju to ponder the truth. The recording had been taken from the bug she had hidden in San-ho's St. Anthony medallion.
San-ho's rage boiled over as he confronted Ethan, assuming him to be the culprit. Accusing Ethan of not only bugging them but also knowing about his plan to flee to Mongolia, San-ho was met by Director Yoo and a contingent of guards who swiftly surrounded him. The director revealed that it was Kim Han-sang, through Valkyrie, who had recruited San-ho as a spy. He blamed San-ho for Mun-ju's downfall and added that San-ho's grandmother was also in their clutches. The director offered San-ho a deal – his grandmother's safety if he could only lure Mun-ju onto the boat to Mongolia, where a coast guard would apprehend her for her role as a spy.
Mun-ju overheard everything through the bug in her necklace, her heart pounding with each revelation. San-ho lowered his weapons and allowed himself to be taken by the guards. However, during the commotion, someone stepped on his necklace, revealing the bug within. As the guards escorted him to an elevator, he took advantage of the chaos to knock them all out and make a run for it.
Returning to the house, San-ho found Mun-ju already gone. She fled through the woods, her heart heavy with regret for ever trusting San-ho. But her misery was short-lived when she received messages from the enigmatic Telegram account, providing her with proof of the nuclear submarine's existence and a location to meet. The anonymous texter held the key to her salvation – and to the truth behind the web of deceit that had unfolded before her eyes.
