Seth Mendoza was the Federation representative during the negotiations for the Barzan wormhole aboard the USS Enterprise-D in 2366. Mendoza was a skilled negotiator and was well respected, particularly by Devinoni Ral, who represented the Chrysalians at the proceedings. However, it was DaiMon Goss who saw Mendoza as the greatest threat to the Ferengi bid for the wormhole and so he allowed Doctor Arridor to use distilled pyrocytes to provoke an allergic reaction in Mendoza. Mendoza fell ill and had to be replaced in the negotiations by Commander William Riker.