Royal Secret Agent has once again reached a new record, beating its previous episode ratings of 6.0 percent and 8.7 percent with episode 8’s ratings of 6.4 percent and 9.7 percent. Just when Sung Yi-gyum (Kim Myung-soo) finally reunites with his beloved Kang Soon-ae (Jo Soo-min), Seo Yong (Park Joo-hyung) and his men ambush them, following the order of Kim Byeong-geun (Son Byung-ho), the Chief State Councilor.
Sung Yi-gyum faces off with Seo Yong
As Yi-gyum duels with Seo Yong, he orders Park Chun-sam (Lee Yi-kyung) to flee with Hong Da-in (Kwon Na-ra) and Soon-ae, but Seo Yong’s men go after them. Fortunately, Choi Do-kwan (Shin Ji-hoon), the Royal Guard who was ordered to investigate Yi-gyum’s activities, arrives in time and saves the three of them. Meanwhile, Yi-gyum is also victorious against Seo-yong, who escaped before Yi-gyum could interrogate him.
Sung Yi-gyum sets a trap
The thief (Yoo Jang-young, The Great Show), who stole from Yi-gyum, goes to the magistrate (Yang Hyun-min) to tell him that Yi-gyum has stolen his coins and is giving them to the people. He also tells the magistrate that Yi-gyum is hiding in the slain nobleman’s house. This, of course, is a trap laid by Yi-gyum. As the magistrate and his men rush to ambush Yi-gyum, they are instead ambushed by Yi-gyum and Do-kwan’s men, who are waiting for them in Lee Cheol-yong’s (Song Yo-seb) house to arrest them. In a fit of rage, the magistrate accidentally confesses to killing Cheol-yong, completely falling into Yi-gyum’s ploy. Yi-gyum orders the magistrate and his men to be taken to Hanyang, so they can pay for their sins.
The townspeople rejoice with Yi-gyum’s victory. Do-kwan goes home to Hanyang, with the prisoners, to report to the King (Hwang Dong-joo) Yi-gyum’s successful mission. By Yi-gyum’s request, Do-kwan hands a ledger to the King, which the team has obtained from the gambling house. The ledger contains all the names of the corrupt officials who received bribes from Lord Cheol-yong. The King then orders that all those in the ledger be arrested.
Sung Yi-gyum is feeling blue
Soon-ae learns that Yi-gyum is a royal secret agent and leaves. Because of this, Yi-gyum gets heartbroken again and falls into depression. He refuses to eat, sleep, and is often sulking. Da-in tries to cheer him up.
The team sails off to their second mission
Instead of going back to Hanyang, Yi-gyum and his team set off for their second mission given by Chief Royal Secretary Jang Tae-seung (Ahn Nae-sang), where Yi-gyum has to meet Governor Kim Myeon-se of the Jeolla province. During their journey, Yi-gyum gets sick, and Da-in and Chun-sam rush to the nearest town to have Yi-gyum treated by an herb gatherer. As Yi-gyum recovers, they discover that a chain of killings and rape cases have been happening in the town, and all the victims are women. Yi-gyum decides to stay and investigate.