Tosin was a Kolaati trader who dealt in illegal substances near the Nekrit Expanse. In 2373, after a prior deal with Wixiban and Neelix had failed, Tosin agreed to spare their lives only if they delivered three grams of warp plasma. Several people were injured and one killed when one of Tosin's men fired his weapon, igniting the warp plasma. Tosin and his men were taken into custody by Bahrat soon after. (VOY: "Fair Trade")