Portal jians are large, immobile creatures that grow in cultivated farmlands and exhibit a physical mystery still unexplained by science: the portal jian's body always contains at least one large hole or gateway that can be passed through for instantaneous travel to a nearby jian's portal. Scientists are unsure how this instantaneous travel works scientifically, but researchers are beginning to map out how a jian decides which other jian(s) to connect to.

Because so little is known about the portal jian, the species' existence is tightly controlled and monitored by the government in secure labs; until they were confident there were no jians left in the wild, the public sector was filled with paid mercenery work to locate and capture these mysterious creatures.