Once again Master Key variety show has changed its style of program after the usual finding the demon-angel key holders seem to bore the audience. First the members will work as a team in finding two keys to open up the treasure box. Their mission is to search for the master trucks parked all over the place and solve a mission. If they succeed a mission, they get a key however it can be a wrong key which cannot open the box. It's all a matter of luck.
Guests include actress Gong Seung Yeon, gagman Park Sung Kwang and remaining permanent members Lee Soo Geun, Jeon Hyun Moo, Kang Daniel, Ong Seung Woo and Key. The members ride a big van together, looking at GPS trying to locate the master trucks. First they arrived at a Hanok village- they are to move around the tables with 4 dishes without lifting up and arrange it exactly the same as what was laid out. It was like solving puzzles. First up was Daniel and Key but their teamwork was rather frail. Second was Soo Geun and Sung Kwang who failed miserably too. Third up was Hyun Moo and Seung Yeon who successfully solved the puzzle and everyone got to eat delicious Buan home cooked meals. Weather was cold and snowy out there in Buan. They received a key and surprisingly the key turned on the treasure box. They screamed happily that they have already solved one mission.
The van drove passed some high school girls where Seung Yeon and Sung Kwang waved to them but received no response. When Seung Woo peeked to wave, there were screaming all over the place. This has proved Wanna One's big popularity! Hah! Soo Geun mentioned the girls didn't see Daniel sitting way behind otherwise the entire van will be put to a stop on the road. The next stop was at a petrol station. Three members must seek out 3 customers and get their names identified correctly to get the next key. Daniel and Seung Woo decided to stay out as they could sense the regional folks do not know Wanna One. Soo Geun goes first and was overwhelmed when an elderly man called out his name three times. Aww...he was so happy shaking his hand. They send out Sung Kwang who looked embarrassed but one man recognised him straight away. Wow! From behind they saw a bunch of younger man walking towards the stop. Sung Yeon headed straight to them and one of them called out her name. Success! Actress is easier to be recognised but they didn't know Seung Woo- dismay! Ha ha!
The key didn't turn the box...so they moved to an onion field. There are 7 rows where the PD tells them to pick each lane and row to the end. That's it? They found it strange. Somehow Key wondered the lanes must be filled with some nonsense to welcome them!
Sung Kwang, Key, Hyun Moo and Seung Woo ran on the safe lanes but when it came to Seung Yeon, it was a slapstick comedy where she fell into a pit. The production casts have dug a hole in the lane and covered with lots of hay! Mission failed so they didn't get any key. Once again, the team drove to find another master truck which is a salt field. They were given fresh steamed red bean buns. Immediately they tried a few buns while Soo Geun asked Daniel what does it feel to eat a nice red bean bun. Immediately it reminded him of his mother. What a sweet son... however they continued teasing him it must be his 'girls'...he'd named the girls Mom 1, 2 and 3....he smiled innocently and said there's no such thing. Pat bing soo were served on the table. They could sense a few bowls of the pat bing soo must be shaved salt instead of ice. To their dismay Sung Kwang and Soo Geun picked the wrong bowls and mission failed. Again they drove to Buan Calderon Museum where they have to feel what's inside the Calderon without seeing it. They send Hyun Moo, Daniel, Key and Seung Woo for the mission. It was hilarious seeing their face expressions when they started to touch what's inside the big vase. It turns out to be steel sponge, pine cones, muk..etc. They received another key and successfully opened the box. However the mission states there are only 6 keys means 1 person has to be eliminated. The unfortunate person is Soo Geun who left in his big van. One of the keys is the main master key where it opens all the boxes of treasure. Sung Yeon's key is the real master key.
In the van, Soo Geun was informed he holds the main treasure box but he has to find the real master key if he wants to win the entire prize. He lurked back to the village and searched for the real master key. He knew Sung Yeon's key was the real one but pretended hers was fake. He managed to convince the rest to hand over their keys to open the main treasure box. PD announced that Soo Geun wins the main prize when he uses Sung Yeon's key. She was shocked to know he tricked her and the rest! Daniel and Key who snugged several keys but it was no use at all.