Triacus
Type:	Planet
Native Species:	Triacus marauders

Triacus was a planet located in the vicinity of the planet Marcos XII and the Federation Starbase 4.

The legend of Triacus stated that the planet was the home to a band of marauders who were making constant war throughout the Epsilon Indi system. After many centuries, these marauders were defeated by the very individuals who they preyed upon. The legend also mentioned that a powerful evil presence remained on Triacus, awaiting for a catalyst to revive it, allowing it to spread its evil across the galaxy. This power was personified by Gorgan, the last of the planet's inhabitants.

In 2268, Triacus was the site of a Starnes Exploration Party lead by Professor Starnes. On stardate 5038.3, one of the archeologists, Professor Wilkins, accidentally released Gorgan during an excavation of a cave near their encampment. It was noted that the destruction of whatever civilization that might have been there was produced by some natural catastrophe.

Gorgan influenced the children of the expedition and caused their parents to commit suicide. Gorgan made a further attempt, and was initially successful, to escape from Triacus aboard the USS Enterprise to spread its evil on to Marcos. (TOS: "And the Children Shall Lead")