Serid's back straightens even more at Ossanlin's tone, but he silently holsters his Dracon and raises his hands to show he means no harm. It is certainly disappointing that the Andalite's strange capabilities would not likely prove much help for someone in his situation, but he has long accepted his choice to become a nothlit, anyway. So why does he feel so pained?
At the unknown Yeerk's hesitant response--a Yeerk who, it is now clear, is anything but just a Yeerk--a small flare of anger is lit inside him. "You should accept his offer," he tells him, his voice flat. "A chance such as this is not likely to come again."
"Sorry, uh, Prince Ossanlin, was it?" Illim winces, peering around Serid. "We're not causing harm or trying to interrupt. We just wanna slip by to have a chat with this Corliss fellow. If you'll pardon us?" He puts a hand on Serid's shoulder to try to steer him forward, or at least shut him up, but the nothlit doesn't budge.
"I thought that, if I was infested," Elayne explains, folding her arms, "no human would believe that I wasn't being manipulated. It was the only way to convince my own race that I genuinely believed what I said I did."