The purpose of their visit was to attempt to sell a stolen item via Quark to a buyer who wouldn't ask questions. However, their purpose was disrupted by the appearance of Croden, a Rakhari fugitive who demanded to be given the item, at gunpoint.
Ro-Kel moved to shoot, but was killed by Croden, leaving Ah-Kel in anguish about the loss of his twin. As a Miradorn, Ah-Kel became vengeful over Ro-Kel's death, and attempted to enact his vengeance against Croden. (DS9: "Vortex")