Retaya was a Flaxian assassin who posed as a merchant dealing in fine fabrics and perfumes. His preferred method of assassination was poison, using perfumes in his collection that could be combined to produce lethal mixtures. Retaya was previously suspected of the murder of Dekora Assan on Japori II, but was exonerated on the basis of mistaken identity.
In 2371, Retaya was hired by the Romulan Tal Shiar to assassinate Elim Garak aboard Deep Space 9. However, Garak knew he was coming and destroyed his own shop, casting suspicion on Retaya before he could make his assassination attempt. Retaya was subsequently executed by the Tal Shiar, who rigged his ship to explode, for failing to kill Garak.
A Tal Shiar operative later willingly admitted to Commander Benjamin Sisko that Retaya was wanted for crimes against the Romulan Star Empire and that his death was justified. (DS9: "Improbable Cause")