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

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

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

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

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

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