In 2050, after nuclear war and resource depletion have devastated Earth, a unified Korea launches a secret space mission to secure a map of the planet’s remaining resources. Dr. Ji-hoon joins the mission as the crew’s physician, hoping to develop a cure for his terminally ill daughter in the sterile environment of space. Two days before returning to Earth, he discovers that there is one more person on board than there should be. When a crew member is found dead, the space station becomes a locked-room murder scene. As suspicion spreads among the astronauts, Ji-hoon must uncover the intruder, survive the mission, and return home to keep his promise to his daughter. Developed as a six-episode OTT drama, 11+1 combines SF, survival suspense, and mystery with strong potential for international co-production and adaptation.