Episode 6 of *The Murky Stream* opens with a bombshell revelation: Jung Chun has been imprisoned. Dol-gae, seething with rage, threatens to end Jung's life, but Jung remains unflinching, his resolve unbroken. And he has every right to stand firm, for Lord Tae-seok soon orchestrates his release by dangling the carrot of a promotion for the General. This only fuels Dol-gae's fury, prompting him to resort to blackmail, coercing his captains into scouring for evidence that could land Jung in genuine legal trouble.
Meanwhile, retribution for Eun's bold move to expose corruption rears its head in the form of roadblocks strategically placed to cripple the Choi family's lucrative salt trade. Tae-seok eventually intervenes, removing the barriers, but the damage is done. Choi, incensed, strips Eun of her status as heir and arranges her betrothal to the merchant Seo Chang-tae. Her brother, with an air of condescension, lectures her on their family's lack of power, a notion that only serves to irritate her further.
Elsewhere, Wang Hae continues his relentless expansion, winning the trust of O-sam, the formidable "forefinger" of the Seogang. He elevates O-sam to the position of "thumb" and forges a formidable alliance.
With just nine days remaining until her wedding, Eun finds herself at a cliff overlooking the river, a place where she once dreamed of elevating Joseon's trade to global prominence. But fate has other plans. Her late mother's prized jade norigae catches the attention of a band of thieves, who quickly corner her.
Just as all hope seems lost, Si-yul materializes out of nowhere, single-handedly dispatching the bandit who dares to threaten Eun and reclaiming the norigae. In a comedic twist, Eun, believing Si-yul to be equally trapped, grabs him in a panic and flees. Little does she know, the bandits, well aware of Si-yul's legendary skills, retreat in fear. Si-yul, amused by the misunderstanding, chooses not to enlighten Eun, allowing her to revel in the illusion that she has "saved" him.
Their escape leads them to the docks, where Eun is taken aback by the workers' distrust of Si-yul's efforts to improve their working conditions. Touched by his plight, she pledges her support and manages to convince the skeptical laborers to seek shelter under the canopies he has erected for them.
Upon returning home, she hears of Si-yul, the esteemed "forefinger" of Mapo, and concedes that she might have prematurely judged him. Similarly, buoyed by their recent interaction, Si-yul brushes off Mu-deok's worries about Wang Hae's territorial ambitions. At their inaugural official "thumb" meeting, Wang Hae strides past them. Mu-deok stands in awe, regaling tales of the Jurchen general, but Si-yul, uninterested, waits patiently outside. Inside, Mu-deok is met with a hostile reception from the other "thumbs," who subject him to bullying, while Wang Hae silently observes the scene unfold.
Meanwhile, Tae-seok reproaches Jung for acting without a strategy. He unveils his true motivation for stamping out corruption: the revenue from trade lines the pockets of moneylenders who, in turn, offer loans to help clients evade mandatory conscription. Without a robust defense, they are vulnerable to assaults. This revelation resonates deeply with Jung, as Si-yul's village had been easily plundered due to a lack of defense.
As the meeting concludes, Mu-deok and Wang Hae are the first to exit, allowing Si-yul to finally catch a glimpse of the Jurchen general's face. Recognition dawns upon him—Wang Hae is the very man who invaded his village, slew his mother, and attacked him. That night, Si-yul clutches a butcher's knife and navigates through the town under the cover of darkness.
Concurrently, Tae-seok leads Choi to his clandestine hideout, brimming with maps that chart trade routes and markets across the land. He enlists Choi's expertise, asking him to weave these fragments into a comprehensive national trade map. In return, he promises to elevate Choi's son to an officer's rank. Tae-seok claims that the map is for the economic betterment of the country, but Choi harbors a nagging suspicion that Tae-seok harbors darker intentions.
Si-yul strides into Wang Hae's office, the air thick with anticipation. By a twist of fate, Jung trails closely behind Dol-gae, who is on his way to a clandestine meeting with the Jurchen, and both find themselves converging at the very same location. From separate vantage points, the two brothers observe the secretive gathering unfold.
Dol-gae, ever the schemer, has meticulously crafted Joseon identity tags for each Jurchen in attendance. Yet, his tone carries a veiled threat as he cautions Wang Hae against overstepping his bounds and challenging his authority. With a menacing glare, he departs, leaving a palpable tension in his wake.
Seizing the moment, Chun readies himself for action, his eyes scanning the room with a predatory gleam. It is then that the brothers' gazes finally lock, a silent acknowledgment passing between them.
Si-yul makes his way towards Jung, only to be met with a sudden and violent onslaught. Jung, consumed by a maelstrom of anger and betrayal, lashes out at his brother, enraged by the revelation that Si-yul has aligned himself with the outlawed. But just as his fury reaches its peak, Si-yul's words cut through the chaos like a knife.
"Wang Hae is the one who took our mother's life," he declares, his voice steady despite the turmoil raging within. The revelation hangs heavy in the air, silencing Jung's rage and leaving him momentarily stunned.
