In the year AD 2225, Kouji Aiba and Aoi Housen are training astronauts aboard the Liebe Delta station situated at the fringe of the Geduld Sea. During a standard descent, unknown saboteurs launch an assault that forces the station into the Geduld—a plasma network connecting all planets like a nervous system and crushing vessels that venture too deep. With every adult on board dead, the juvenile crew must endure a perilous return across the vast expanse of space toward their home planet, a trek that will test their resolve while internal discord escalates. Meanwhile, the saboteurs" planners observe from afar and ready themselves for another strike in the near future.