As Eve's new state prevents her from coming back to Earth, Ryong commits to joining her in space. Once there, they debate a risky return to Earth.

The consequences of the experiment in space finally manifest, leaving Ryong devastated. Later, Eve learns that her life is about to change forever.

A deployed investigative team discovers Ryong's cell phone in space — sparking an inquiry into who is responsible for the unauthorized events there.

Chief Kang summons Ryong and Kang Kang-su regarding their forbidden experiment in space. Eve uncovers a painful truth about her past.

Choi Go-eun confronts Eve after encountering her at Ryong's place. Chief Kang advises Eve not to see Ryong again — despite Eve's true desires.

While Ryong and Eve adjust to normal life, Chief Kang requests a detailed report of their time in space — leading them to agonize over their story.

Despite their promises in space, Ryong and Eve return to earthly realities — facing duty, recovery, suspicions, confessions and lingering longing.

With Ryong and Eve stranded in space, those on Earth scramble to save them — albeit for different reasons. Park Dong-a steps forward to take the risk.

Eve risks everything to heroically rescue Ryong, facing treacherous danger. However, returning home seems increasingly improbable.

After Ryong learns the results of his experiment, a potential calamity approaches the crew — threatening his safety and the survival of his work.

Eve discovers an unethical secret, forcing her to act decisively despite Ryong's objection — which drives him to take matters into his own hands.

Following Ryong's sudden confession, Eve discovers a hurtful truth unfolding back on Earth. Soon, she learns of an even more disturbing reality in space.

With Eve's life in jeopardy, Ryong watches helplessly — as protocol prevents him from saving her. With every passing second, she loses precious oxygen.

Determined to carry out the secret mission himself, Ryong tries to circumvent Kang Kang-su. During a space walk, Eve experiences a sudden problem.

Upon arriving in space, Ryong panics as Eve threatens to ruin his secret mission. Shortly after, a crisis emerges, forcing Ryong to attempt a novel feat.

Coming from two different backgrounds, Gong Ryong and Eve Kim embark on a space mission. But trouble strikes after launch, jeopardizing their expedition.