The Metrons were a powerful, enigmatic race.
The Metrons were first encountered by United Federation of Planets representatives in 2267. In that year, Captain James T. Kirk had ordered the USS Enterprise to pursue a Gorn vessel that had destroyed the observation outpost located on Cestus III.
As the pursuit passed the uncharted star system at 2466 PM, the Enterprise was scanned from that system. Then the Gorn vessel inexplicably slowed and stopped. Thinking they planned to fight, Kirk prepared to engage – and then the Enterprise likewise slowed and stopped. Both ships were being held in place from the star system at 2466 PM, not by tractor beams, but rather by "an unidentifiable power".
The Metrons, declaring both species savages, prepared a planet and removed the captain of each ship to it. There, they were to fight to the death, and the outcome of this contest would determine which ship survived, and which was destroyed.
Eventually, Kirk won the fight, but elected to spare his helpless opponent. This demonstration of mercy surprised the Metrons, whose analysis of the situation did not lead them to expect it. A Metron appeared to Kirk, and suggested that, although the Federation was still half savage, there might be hope for it in a few thousand years. The Metrons then returned Kirk to the Enterprise and transported the ship 1,600 light years away from their space.
The Metrons demonstrated the ability to manipulate forms of energy unknown to Federation science, to perform comprehensive scans at great range, to transport matter great distances instantly, and perhaps to rapidly terraform planets to specific requirements. All of these feats were well beyond what even 24th century Federation technology could accomplish. This suggests their science and technology was hundreds or thousands of years more advanced than that of the Federation.
Metrons had long life spans; the representative that met Kirk was approximately 1,500 years old, despite appearing as little more than a boy. His comment to Kirk suggests an interest in the political and sociological geometry of the galaxy thousands of years hence. It is possible that this perspective was a consequence of this long life span. (TOS: "Arena")
- No Metron characters were ever assigned names in canon productions.