This is a summary based on our understanding of the series.
Please also note that this summary contains spoilers.
The Kim family is poor. They rely on free wifi and they are cramped in a very small and untidy house. Kim Woo, the son, received a gift from his friend and a job offer to tutor a rich family’s daughter. With the help of his sister to forge documents to be qualified, Kim Woo applied for the job and got hired by the Park Family.
Kim Woo talked to the mother of the Park Family, Yeong-yeo, and recommended an art tutor for the Park’s youngest son. Kim Woo hid the fact that the person he is recommending, Jessica, is his sister. Jessica was later on hired by the Park Family to tutor the son, Da Song.
There was one night that the father of the Park Family, Nathan, met Jessica – he asked his driver to take him home. While in the car, Jessica took off her underwear and left it inside the car. Nathan later on found that underwear and fired the driver. Jessica talked to Yeong-yeo, and recommended a driver. The driver Jessica recommended was their own father, Mr. Kim.
Mr. Kim started working as Nathan’s driver. Now, only their mother, Chung-sook, is not yet employed. They planned to oust the existing housekeeper by making it appear like she has tuberculosis. She is allergic to peaches, so they sprinkled particles from peaches on her until she had an allergic reaction – which makes it appear like she really had tuberculosis. When the mother of the Park Family fired the housekeeper – Mr. Kim recommended Chung-sook as a housekeeper. Finally, the the entire Kim Family is now hired by the Park Family.
During the Da Song’s birthday, the entire Park Family planned for a camping trip. The Park Family went away for the night, and the entire Kim Family enjoyed the house by themselves, and drunk in the living room. In the middle of their drinking, the doorbell rang. When Chung-sook looked it, it turns out to be the previous housekeeper – Moon Gwang. Moon Gwang asked if she could get something that she left from the basement, she left it because she was asked to leave hastily by the Park Family.
Although hesitant, Chung Sook allowed Moon Gwang to enter and go to the basement. The rest of the Kim Family hid and waited for Moon Gwang to finish getting what she needs to get. It was taking her longer than usual, so Chung Sook also went to the basement and found Moon Gwang trying to push aside a large cabinet. Chung Sook helped, the cabinet was moved aside, and a door was revealed. It was a door leading to an underground room. Moon Gwang was yelling “Honey” as she entered that door and ran inside. Chung Sook followed and was stunned to find out that there was a man hiding there. Moon Gwang hurriedly fed him a bottle of milk and a banana.
Moon Gwang explained that it is her husband, and he has been hiding there for about 4 years. Moon Gwang was the housekeeper of the previous owner of the house, before the Park Family came, so she was the only one who knows about this secret room. Moon Gwang’s husband can’t go out because he has a lot of debt, he asked Chung Sook if she could pay her in return of feeding her husband. Chung Sook disagreed, and threatened to call the police.
While Moon Gwang was pleading not to call the police, the rest of the Kim Family fell down the stairs while they were eavesdropping and revealed themselves to Moon Gwang. Moon Gwang was also able to take a video of them, with Kevin yelling out “Dad.” Now it was Moon Gwang who’s threatening them.
Moon Gwang had the Kim Family kneel as she threatened them to send the video to the Park Family. However, Mr. Kim lunged on them and they fought.. as they were all fighting in the living room, the telephone rang. It was the Park Family Mother – she asked Chung Sook to cook noodles because they’ll be going home. The rain was pouring hard and they could no longer go camping. They’ll be home in 8 minutes.
They scrambled to clean up the house. Moon Gwang’s husband was kept in the basement – and Moon Gwang herself was pushed by Chung Sook, and she fell down the stairs towards the underground basement. Chung Sook served noodles, the rest of the Kim Family hid, and Moon Gwang bled in front of her husband. Moon Gwang eventually died and before she died, she asked her husband to remember that it was Chung Sook who pushed her down the stairs.
The rest of the Kim family was able to escape the Park’s family house, but when they went home – they found that flood water has entered and most of their things have been drenched. They ended up sleeping in the gym.
The next day, the Park Family decided to host a party for Da Song since it was such a beautiful and sunny day. They invited their friends. They also invited each of the Kim Family. Even though they barely have clean clothes to wear, they attended the party.
Mr. Kim was with Nathan, getting ready for a surprise number for the party, Jessica will be serving the cake for Do Song to blow, Chung Sook is busy attending to the gets. Meanwhile, Kevin was kissing Da Hye (Park’s Family Daughter) but he was thinking of something else. He bought the large rock that he got from his friend, Min. After kissing Da Hye, he excused himself and went to the underground basement with the rock in his hand. The rock accidentally fell off his hand, and when he was about to get it, Moon Gwang’s husband appeared from behind and dragged him by the throat using a wire. Moon Gwang’s husband also ended up throwing the rock at Kevin’s head.. and he was left bleeding as Moon Gwang went out of the basement, took a knife, and proceeded to the party to look for Chung Sook. Moon Gwang stabbed Jessica – when Da Song saw Moon Gwang, he had a seizure.
Seeing his son having a seizure, Nathan hurried towards him and ordered Mr. Kim to drive them to the hospital, but then Mr. Kim was still attending to Jessica who was bleeding heavily. Mr. Kim threw the key at Nathan. Chung Sook appeared and stabbed Moon Gwang’s husband with a skewer.. killing him. Mr. Kim saw Nathan’s disgusted reaction at Moon Gwang’s husband’s smell.. and he proceeded to stabbing Nathan. After stabbing Nathan, he walked away from the house.
Jessica died. Kevin recovered from his head injury but he had a condition where he could not control his laughter. It was now only Chung Sook and Kevin living together because until now they do not know where Mr. Kim escaped..
After Kevin recovered from his injury, he continued watching the Park’s family house from afar. The Park Family has gone, replaced by another family. One time, he felt like staying a bit longer even when it is already dark.. he saw the lights flickering. He remembered that Moon Gwang’s husband used it for morse code. Kevin took notes from the lights and transcribed it on the way home.. and he discovered that his father is there. When he escaped, he simply went inside again via the garage. He has been hiding there ever since that day and has been secretly taking food from the refrigerator at night.
Kevin daydreamed of a plan where he earns a lot of money and buys the house where his father is hidden.. and one day when he finally bought the house, his father would come up, see the sun, and find Kevin and Chung Sook waiting for him by the lawn.
The End of The Weekend Away Movie.