Fenri is a Knowledger, a brilliant collector of information who dreams of discovering the ocean’s secrets. The tribe’s Masters grant her permission to explore the ocean, but only if she first traverses the perilous desert with four strangers to retrieve a precious base metal. Despite a condition that makes her slower and weaker than her counterparts, Fenri accepts the mission, eager to prove her worth. She will succeed or die trying.

When hormone-sniffing beasts begin stalking their group, it’s clear that someone has opened their fourth portal. Determined to protect her chances of exploring the ocean, Fenri vows to find and eliminate the traitor before the love virus spreads. As forbidden feelings surface, the group begins to unravel, turning their mission into a race to close the fourth portal before the beasts or their fellow tribesmen end them. That is, if they don’t kill each other first.