"Duel" unfolds with Issei packing up his business affairs, a compelling narrative that reveals his expulsion from the family's esteemed venture, Drops of God. As he addresses a reporter named Yurika Katase to make his official announcement, Issei declares his withdrawal from the competition, dedicating his life instead to the family business, Tomine Diamonds. Yurika, dismayed by Issei's decision and the wasted opportunity for her, urges him to reconsider.
In France, Camille has five days left to hone her skills. She's rediscovered her palate and is testing every wine within her reach. Camille has managed to identify more aromas, including celery root, yet they remain unable to locate the actual wine. Thomas and his father debate the possibilities of a wine with celery root aromas. Philippe recalls a strange wine crafted by Andre Gigon called Lignage, which he believes could be the one they seek. They research the wine and discover that Gigon went bankrupt, selling off all his bottles. The last bottle was sold for ten thousand dollars online.
Camille is leaving for Tokyo that night, and they have only hours to track down Gigon. Thomas drives them to Gigon's home, where they discuss relationships on the journey. Camille finds it challenging to socialize due to her abstinence from alcohol. Gigon's son suggests that Camille may have tasted a Lignage from 1987.
In Tokyo, Camille reunites with Luca, and the competition is all over the Japanese news. Luca introduces Camille to his nephew Lorenzo, who is training to become a sommelier (a wine waiter). Camille believes she knows what the wine from the first challenge was but needs to taste it to confirm her suspicion.
Luca tracks down a Lignage 1990 from one of his restaurants in Osaka. They plan to serve this bottle, which costs twelve thousand dollars, to a wealthy businessman named Mr. Matsubara. Miyabi and Lorenzo train Camille in serving wine, but her father taught her the art when she was just eight years old.
That night, Camille uncorked the expensive bottle of wine, and while Mr. Matsubara was preoccupied, she sniffed the aroma. Camille needed to taste it to be certain. They waited until the meal was over, and Camille extracted the last drops from the bottle. She tasted it and concluded that it wasn't the right one. She informed Thomas over the phone, adding that she missed him.
Issei's grandfather urged Honoka to persuade Issei to drop out of the competition. Honoka asked her husband Hirokazu to convince their son to announce his withdrawal. Issei realized that wine was his life and refused to quit the competition.
Thomas flew out to Camille to help her win the competition with only 48 hours to go. Lorenzo and Miyabi offered Camille many different wines to taste, but none seemed to be right. They went to a karaoke bar to clear their minds, and Thomas had a light-bulb moment. It wasn't celery root that Camille was smelling; it was actually truffle.
This narrowed down their options to two possible wines, although the vintage (year) was still unclear. Both Issei and Camille headed to Alexandre's home for the conclusion of the first round of the test. Issei drank the wine and made a super quick decision. Camille took longer, sniffing and inspecting the drink.
Camille chose Chateau Cheval Blanc 1999 but then hesitated and changed her answer to 2000 instead. The answer was revealed. They guessed the correct wine, but Issei chose 1999, and Camille chose 2000. Issei was the winner; it was extremely close.
The results of the test were announced on the news. Issei's grandfather was furious that his grandson ignored their requests and continued with the tests. Honoka spoke to Hirokazu over the phone, angry that her husband couldn't convince Issei to drop the game.
In the final moments of the episode, Hirokazu asked for an envelope and placed his key belongings, including his wedding ring, inside it. This implied that Hirokazu was going to commit suicide after receiving abuse from both his wife and son throughout the week.
