Eris was a Vorta agent in service of the Dominion. She was involved in an attempt to infiltrate the Federation in late 2370. She was the only Vorta known to apparently possess telekinetic abilities. She claimed she was from Kurill Prime.
While Benjamin Sisko and Quark were on a camping trip in the Gamma Quadrant with Jake Sisko and Nog, Eris appeared at the campsite posing as a refugee from the Dominion. She claimed she was a Kurillian who was on a freighter heading home when their homeworld was conquered by the Dominion. The freighter fled from the Dominion; however, the Dominion pursued the ship as it was carrying Eris. Eris' mother was an outspoken opponent of the Dominion, and, in the opinion of Eris, the Dominion wanted to make an example of the family by the capture of a family member. The three of them were then captured by the Jem'Hadar, allowing Eris to gain Sisko's trust. Eris was apparently fitted with a telekinetic suppression collar, and she helped them escape after Quark unlocked the device.
However, Quark later discovered that the collar was nothing more than a complex locking mechanism, while attempting to strip it and sell the plans for profit, and that Eris could have helped them at any time. Her true mission exposed, Eris escaped from Deep Space 9 via a transporter. (DS9: "The Jem'Hadar")