Yes, Ahan is a traitor. When building this book, I knew that I wanted one of the characters to betray the rest. I also knew that I didn’t want it to be the most obvious one in the group. This left me with a problem. I had to provide a character whom nobody would suspect as a traitor, yet at the same time make it believable that he would turn traitor.
The first thing I did was throw in Edan as a diversion. He worked perfectly–virtually all of my alpha readers mentioned that they thought for certain that he would turn traitor. I had Edan run off early because I wanted to lull the readers into a sense of security, thinking that their ‘traitor’ character had disappeared already. I also didn’t want to throw Ahan’s betrayal in with Edan still there–I think that would have made Edan’s purpose too obvious to those who could see the two contrasted that way.
The next thing I did was begin foreshadowing that Ahan acts, and speaks, without thinking through his actions. I mention this a couple of places, including at the eclipse party. I made his character a bit indifferent, a lot blustery, and tried to indicate that he didn’t quite see the treason he was engaging in as being as dangerous as it really was.
Finally, I began having him act suspicious. You can go look through the spoiler annotations if you want notes of where I had him doing things like this. Essentially, he acted odd when Telrii was mentioned, and he was the one who went to visit Telrii when the group wanted one of their party to get in good with the enemy.
These are small things, I realize. However, I think they work well enough. I wanted to get across a sense of shock and surprise at the betrayal. I always hate it when traitors are obviously oily men with shifty eyes. I don’t think people trust that kind of man.
Anyway, I think the other thing that lets me get away with Ahan’s betrayal is that he doesn’t completely change characters with the treason. He isn’t a different person–he doesn’t suddenly become a ‘bad guy,’ like happened in some stories. (Ahem. The TV show 24, first season.) Ahan just didn’t think hard enough about what he was doing–he took his actions too lightly.