The Marauders of Triacus were space pirates who terrorised the worlds of Epsilon Indi for centuries. Their motto was: "We take what is ours wherever we go." After enduring centuries of depradation, however, these worlds united and overturned their oppressors, exterminating the Marauder race utterly--as it seemed.
Their home planet Triacus was in or near the Epsilon Indi system. The sole surviving Marauder specimen, named Gorgan, lingered here as a noncorporeal being within a cave near the surface. The cave was discovered in 2268 by the innocent Professor Wilkins of the Starnes Exploration Party. Wilkins' excavation freed this last Marauder and spelled doom for the party.
The last Marauder of Triacus, in noncorporeal form
The phantasmal Gorgan can exert mind control, perhaps through the power of illusion. He causes expedition leader Starnes to contact the Federation to request transport, but neglects to provide him with a rationale and the ruse fails. The adults are too strong of character to manipulate completely.
But Gorgan can also thoroughly cow his human victims, somehow able to sharply evoke "the fear in each one of them". As he tells the party's children, whom he purposes to lead, "Anxiety is the beast which will consume them". After he extracts from Starnes a no-doubt genuine distress call to the USS Enterprise, Gorgan drives the party's adults to commit suicide.
Five Federation couples, consumed by the Beast
He now plans to ride the children like horses onto the starship and further dominion. (TOS: "And the Children Shall Lead")
- The Triacus Marauders are different from the Klingon ones who extort from the mining colonists visited in the 2nd season Enterprise episode. Nor could Captain Archer have run into Gorgan's race anyway, as they were most likely already extinct: only eleven decades later, Commander Spock regards the story of the Triacus Marauders as uncreditable legend.