Girls Planet 999: The Girls Saga

The episode begins with the girls attending a fan meeting with some viewers of the show. They perform several of their past performances from the Planet Demo Stage and the previous two missions. After the fan meeting, the girls give presents to the audience.

The episode then begins to the commencement of the Creation Mission performances. After the performances, the winner is announced. Then, it is revealed that the real final mission is named the O.O.O Mission which will take place during the finale episode. Further details are revealed; the girls will be first organized into 3 different groups that will perform a debut group version of the show's theme song, "O.O.O (Over&Over&Over)". The teams were voted for by the viewers through Universe.

The episode begins with the O.O.O Mission. The girls are grouped into three different teams; two containing nine members and third containing eight. The girls arrange their parts and practice their performance. After practice, they perform their performances to the mentors. In between performances, the girls are shown video messages and performances by viewers of the show from around the world.

The winners of the O.O.O Mission were determined by the viewers of the show; the contestant of each team that accumulated the most number of YouTube likes on their respective video within 24 hours would obtain a benefit of 90,000 (nine-member) or 80,000 points (eight-member). The winners of the O.O.O mission are revealed.

The episode then proceeds to the third ranking elimination. After the seventeen survivors are announced, the Planet Pass recipient is then revealed.

The episode ends with the preview of the final episode's mission.

The episode begins with the 18 finalists performing the show's theme song. Due to COVID-19 safety measures, the only live audience was the mentors along with some of the eliminated contestants who were still in Korea at the time. There was also a live Zoom audience who was occasionally shown.

After the theme song performance, the show's host announces the opening of the final voting round, in which all live votes will be doubled. Following this, the audition and highlights videos of the 18 girls are shown. Voiceovers by the girls during the videos also explain why they are pursuing such a career, expressing their desire to debut. Host then explains the live voting process, stating that the final votes will include the first round votes from the week added with the final second round live votes. A segment then takes place where host interacts with members from the live Zoom audience. He then introduces the mentors as well as the live audience consisting of some eliminated contestants. The current 9th place candidates are then announced.

The episode then cuts to a few weeks before the finale; the 18 girls are introduced to the Completion Mission song "Shine". They learn that two teams of nine will be formed, with both teams performing the same song. The lowest ranking contestant goes first to pick which team they want to join, followed by the rest of the contestants in ascending rank order. The girls then settle their parts and prepare for the finale. Host then announces the debuting girl group's name. Afterwards, the 18 girls then perform "Shine".

After the performance, the episode cuts to a week prior where the girls watch their audition videos. They also watch videos aimed to their future selves that they filmed when the show began, as well as similar videos filmed by some of the eliminated contestants. The girls then perform "Another Dream", a pop ballad song. 

The episode then cuts to the days leading up to the finale. The girls are treated to a party where they reviewed artworks they created for one another as well as receive a lavish dinner. Afterwards, they also view polaroids that serve as memories of their time participating in the show. They then settle in front of a projector and watch video messages by some of their parents.

Host then begins to announce the debut lineup of the group. The episode comes to a close with the debuting and eliminated girls coming together, congratulating each other and exchanging hugs.