In the future, interstellar travel takes place via "inflation gates" that pass through a parallel universe. Unfortunately, denizens of another universe, called "ghouls", want to invade our universe using the same portals. At Watcher's Nest, a distant station, a ship arriving through a portal is attacked by a ghoul, and one of the passengers, rookie soldier Kureha Misaki, undergoes a dreadful change.
