A woman in the episode Rivals who persuades the El-Aurian confidence man Martus Mazur to put his money into her mining scheme and then disappears with it.
Alsia is a traveller seen in the second-season episode Rivals. She first meets Martus Mazur in a bar on Deep Space 9 and tells him about an asteroid mining venture she is trying to finance, the sort of sad story Martus is used to turning to his own profit.
For most of the episode he is occupied with his new club and its luck-altering gambling machines, which draw Quark's customers away until the devices are found to be distorting probability across the station and are destroyed.
Flush with his takings, Martus finally puts a large sum into Alsia's project. She was running a swindle of her own all along and vanishes with the money, so that the listener who always took advantage of others ends the story cheated in his turn.