In the seventh episode of The Murky Stream, Jung implores Si-yul to abandon the life of a bandit and promises to bring Wang Hae to justice through legal means. However, Si-yul refuses to flee, claiming that he is part of a family. Next, Jung informs Tae-seok of a conspiracy theory that Japan is planning an invasion, a claim that initially goes unheeded by everyone, including Jung himself. But Tae-seok presents him with "proof" – new Japanese artillery, and shares the details of map creation for their defense.
Elsewhere in the tale, Choi informs Chief Kang of Tae-seok's desire for the map for the country's economic welfare. While skeptical, Kang agrees to locate painters. Choi, weary of his son wasting time studying, decides to give Eun a second chance, but warns her that ambition is futile. That night, Walwal intercepts Si-yul returning and reveals the truth – Wang Hae killed Si-yul's mother. The loyal bandits are enraged and determined to seek revenge, despite Mu-deok and Si-yul's advice to the contrary. The bandits disregard their counsel and set their sights on Wang Hae, strategizing on how to take him down.
Meanwhile, painters start pouring into Tae-seok's residence, news that reaches Dol-gae, who immediately reports to his lord. The mysterious minister orders Dol-gae to steal whatever Tae-seok is doing. When Tae-seok is gone, the minister's patron, the Queen Mother, orders him to eliminate Tae-seok, believing he is plotting a rebellion with his Japan conspiracy.
After weeks of preparation, the bandits make their move. Mu-deok finally notices but it's too late; the bandits have already vanished into the shadows.
Even before Wang Hae's arrival, the attack went awry, and upon his arrival, he swiftly dismantled the bandits with ease. They made a desperate dash for freedom, but he refused to let them escape. He confronted Mal-bok, who stood firm despite the odds being heavily against him. The remaining bandits scurried home, but upon realizing Mal-bok was missing, Si-yul pursued him. However, it was too late; he arrived to witness Mal-bok taking his last breath. Enraged, Si-yul launched an attack on Wang Hae. Though skilled, he was no match for Wang Hae's prowess. Just as he was about to be defeated, Mu-deok arrived with Jung, who arrested Wang Hae. The bandits were overcome with grief as they mourned Mal-bok's loss. Eun was by the docks when she saw the funeral procession and felt a pang of sympathy for Si-yul. Even as everyone else left, Si-yul remained by the docks, feeling a heavy weight of guilt on his shoulders.
