He wasn't fond of the drow, but he didn't hate him. In fact, most of his machinations, while purely selfish, usually helped Zenithral, Alalla, and the others in the long run. Fenthick's words about mercy also ring in his mind. The slaad was one thing, but this dark elf ultimately wasn't much different than Zenithral was. Ilmadia and Zariel could be swayed. In the depths of hell, perhaps there was hope for him yet. At the very least, they'd have a chance to free the orcs from Gruumsh's influence.
"We shall accept a deal," Zenithral declares, almost more to the spiders than to Nym. "Our mission is important. If you can learn and tell us the consequences that exchanging the eye will have, then we will make the exchange." Zenithral tilts his head and glances at Alalla to see her reaction. "We may ask for an additional favor from you as you proposed if we deem the consequences particularly significant, but that is our offer, unless any of my companions object."