Episode 13 of "Seoul Busters" kicks off with the team diving into the investigation of a petty theft incident at an apartment complex. Thanks to Yu-bin's swift and astute deductive reasoning, he swiftly narrows down the list of suspects. He surmises that the culprit behind the heist is likely a high school student residing in one of the apartments, theorizing that the student and his buddies had robbed a nearby convenience store and retreated to the apartment to munch on their ill-gotten snacks.
With a solemn promise, Min-seo assures the affected grandfather that she will retrieve his transit card, which holds sentimental value beyond its monetary worth – it contains the last remaining photograph of his deceased daughter. The elderly man is unfazed by the disarray but is desperate to reclaim his cherished possession.
Jong-ryeok grumbles about the futility of spending time on such a minor case, but when confronted with the option of paying off his debt, equivalent to the amount stolen in the robbery, he finds himself empty-handed. His colleagues seize the moment to playfully tease him, while Tan-sik drifts off into a slumber. His sleep-talking mocks the team members, prompting them to rouse him from his nap.
As Min-seo heads back home, she encounters her sister busy preparing a meal for their prison-bound father. Min-seo's anger boils over as she witnesses her mother and sister's unwavering commitment to visiting him behind bars. Since her father's exposure as the notorious thief, Min-seo has distanced herself from him. The tumultuous period following his arrest, when she was still in high school, left her scarred. She endured months of police harassment, probing into her father's whereabouts, and harsh judgment from her peers.
Elsewhere, Hyun-woo approaches Yu-bin with a request to delve into a fresh case concerning Han Jun-ho, a man implicitly linked to harming Yu-bin's beloved in flashbacks. Naturally, Yu-bin's interest is piqued, and he promptly sets out to uncover the truth behind the enigmatic case.
The following day, Commissioner Hee-ryong approached Yu-bin with a favor to delve into a perplexing theft. An invaluable masterpiece of cultural significance had been pilfered from the esteemed collection of Kim Jong-soo, one of the country's renowned art collectors. The team assembled for a detailed briefing on the case, speculating that the perpetrator could be Jong-soo himself or a family member privy to the vault's passcode. With Yu-bin's encouragement, Min-seo opted to stay behind and concentrate on a lesser robbery, allowing the rest of the squad to proceed to Jong-soo's residence.
Upon arriving, the team was mesmerized by the breadth and depth of Jong-soo's collection. Jong-ryeok's cluelessness shone brightly when he mistakenly mistook a cooling bowl for a beverage cup, earning him a moment of embarrassing humiliation. Tan-sik then unveiled their suspicion, casting aspersions on Jong-soo's wife.
Adding insult to injury, Jong-ryeok's clumsy antics with Jung-hwan culminated in the accidental shattering of an antique. Predictably, Jung-hwan swiftly disassociated himself from the mishap, leaving Jong-ryeok in a panic, worried about the staggering 20 million Won he owed for the damaged artifact.
Thankfully, Yu-bin's sharp eyes detect two peculiar aspects about the antique, prompting him to embark on an investigation. To his astonishment, he uncovers that the antique is a fake, bringing a sigh of relief to Jong-ryeok, who now knows he won't have to mortgage his house or take out a loan. Armed with this fresh revelation, the team redirects their suspicions towards Jong-soo's son-in-law.
Meanwhile, Min-seo is hot on the trail of the suspect in her robbery case. She corners him and his accomplices in the act of stealing from a convenience store once again. The youthful perpetrator reveals that he sold the transit card to a stranger at the train station. Determined to uphold her promise to the elderly victim, Min-seo begins her search for this mysterious man. Yu-bin cautions her to stay detached from the case, but Min-seo's mind is also occupied with thoughts of her father and her sister's advice to forgive him.
The following day, the team confirms their suspicion that Jong-soo's son-in-law, Hyeon-guk, is indeed linked to the robbery. Evidence of his guilt is found in the fur of his dog, left inside the shattered fake antique. They delve deeper into Hyeon-guk's background.
During his questioning, Hyeon-guk admits to stealing some of his father-in-law's antiques but vehemently denies stealing the painting. Later, as the team enjoys dinner, Yu-bin shares his hypothesis that Hyeon-guk didn't steal the painting. He finds it peculiar that Hyeon-guk didn't replace the stolen item with a counterfeit, as is his usual modus operandi.
The next morning, Tan-sik and Jung-hwan return to Jong-soo's residence to conduct further inquiries. A neighbor reveals that a week before the incident, someone called the emergency services to report wasps, though nothing was ultimately found. The team shifts their focus to Jong-soo's maid and the HVAC repairman, Min-yong, who visited the house in the preceding week.
Jong-ryeok and Min-seo visit Min-yong at his workplace for a chat. With a history of special larceny and a criminal record, he certainly raises eyebrows. Despite their suspicions, they can't discount the fact that Min-yong didn't know the passcode. He insists that he simply did his job and left. However, upon revisiting Min-yong's records, Yu-bin uncovers something deeply suspicious.
