The cast arrive at their hotel in Bali, Indonesia. They leave their luggage in their shared living room and go to eat. Upon returning to their room, they find that their luggage is missing and has been replaced with backpacks. The cast are told that they have traveled back in time to 2002, when they were still trainees. Because of this, all their electronic devices are confiscated and exchanged with devices that were present in 2002 such as MP3 players and non-smart mobile phone. They are given instructions on how to return to the present time; by carrying out the tasks given to them, which includes filling up a photo album with photos taken at specific places, and composing a theme song for their trip.

The cast are assigned roles for each other to ease their trip. Changmin is placed in charge of the cast's allowances and spending, Shindong of photography and cameras, and Donghae of the guitar. Yunho is the porter; he keeps their passports and is responsible for snacks, Leeteuk is their first aider and Eunhyuk is their tour guide. The next day, they take a flight to Yogyakarta. After settling in at the hotel, they book a van for easier means of travel. Changmin starts to feel pressured by his role as the cast have to pay for their transportation methods themselves.The cast go to Borobodur, the biggest Buddhist temple in the world. Leeteuk tries to haggle for a cheaper entrance fee but he is not successful.

The cast was amazed at the size of Borobodur. They climbed the steps to the peak of the temple, while admiring the carvings on the wall and the architectural build of the stupas. They took a picture at the stairs, checking off their first task. In the evening, they went to eat at a restaurant that served Korean food, after Changmin's protest of the food being expensive was dismissed through a majority vote. Donghae won the rock paper scissors game at the restaurant, and get to order a meal of his choosing on top of other meals. He ordered samgyeopsal, much to Changmin's chagrin.

The cast reconvened at the hotel as the day ended. They started brainstorming about the theme song they were supposed to write. They also decided on a cheer for the trip. The next morning, Yunho was checking his stock of food when he realised one of the cup noodles was missing. During the journey to their next destination, Yunho confronted the rest of the cast about the cup noodle. Leeteuk, who had eaten it in the morning, tried to deflect the questions directed at him, making the cast correctly presumed he had eaten them. The cast arrived at the base camp of Mount Merapi. They rented jeeps and toured around the mountain. They visited the Sisa Hartaku Mini Museum, which displayed the recovered artifacts from the volcanic eruption in 2010.

The cast arrived at the Bunker Kaliadem and explored it for a while. Then, each of them took a picture with a tame owl. Leeteuk, who is afraid of birds managed to overcome his fear and completed the task. It was raining heavily as they went down the Mount Merapi. The cast experienced rough terrain ride as they passed the Kali Kuning river a few times. In the evening, they went to have dinner at a restaurant at Jalan Malioboro. The cast talked about their rivalry and jealousy towards each other's group. Donghae and Yunho apologized to each other for ignoring each other's text when they were busy preparing for debut back then. The cast recalled on how watching the other's accomplishment always urging them to work harder as they are each other's pacemaker, and how lucky they are, to be able to laugh and talk about it without hard feelings years later as they had successful careers.

It is their third day in Yogyakarta. The cast departed early from the hotel to the next destination. During the journey, Leeteuk pretended he was hosting a morning radio show, with Yunho as guest, Eunhyuk as the foreign correspondent and Shindong as the weather presenter. They arrived at the entrance of the vertical cave, Goa Jomblang, which is located at Gunung Kidul Regency. The cast except Eunhyuk, hesitated to go down the cliff, especially when they saw that they will be lowered by ropes, which was operated by manual labour. The cast managed to curb their fear and went down without fanfares. Donghae admitted that it was a quite difficult for him as he had both acrophobia and claustrophobia. The cast trekked for a while before arriving at the cave opening. In the post-credits scene, the cast were shown to take a group picture before their descent but nobody beside Eunhyuk was smiling.

The cast entered Goa Jomblang. The cave floor was muddy, making it very slippery. Leeteuk had muds entering his boots as he went knee-deep into the mud. The cast arrived at the part of the cave that was dubbed as "light of heaven" because it has a ceiling opening where light can shine through, which created a beautiful scenery. The cast took individual pictures under the light but they were unable to take a group picture as the light faded. During the returning trek, the cast realised that Yunho was being quiet. He denied that he was tired when asked by the worried cast members. In the talking head interview, Yunho admitted that he was experiencing headache, dizziness, and signs of panic attack. He said that the atmosphere in the cave reminded him of his near-death experience, when he was poisoned with super glue by an anti-fan back in 2006.

The cast were dressed in wetsuits as they prepared for river tubing at the Kalisuci cave, which is a river cave. Shindong, who is afraid of moving water, was determined to face his fear despite the cast assuring him that it is okay to opt out of the activity. Shindong took the lead in tubing after a short discussion among the cast. They all agreed that Shindong might be afraid to have a go if he saw how the other went ahead of him.

In the evening of the third day, the cast went to have dinner at an open air restaurant, which had a great view of Yogyakarta. The cast took a picture there and wrote the day's diary memo detailing their experience.

Donghae, Shindong and Yunho took turns paragliding. Donghae, who has acrophobia went first.

The cast were overjoyed that their electronic devices were returned to them. They held a discussion about the activity they are going to do on their final day in Indonesia.

The cast members returned to their busy life after they returned from Indonesia. During the lull in his schedule, Leeteuk met up with his frequent collaborator in composing, Team One Sound, to choose the music for the soundtrack from their list of compositions.