I need a myth

[Rechan]

Interestingly, the PCs are all ready suspicious of the guy. They however just think two tribes have a feud and he's trying to get them on his side, make war with the "enemy". They are, next session, going to seek out the "enemy" to get their side of the story. At which point the sneak is just going to slink away - he's going to get found out soon. Fortunately, two of the PCs are still teaching him their language, which was his initial goal.

Part of the challenge of "betrayal" at least in the context of this game is that there are a lot of monsters that can do the "hey I'll lure you over here with this HA GOTCHA". For instance, in one monster book I found a puppeteer spider, which uses its webbing to make corpses do rudimentary actions, and it can mimic noises. Pull too many of these tricks and the Pcs are going to be suspicious of Everything.

 

[Gilladian]

I find that my PCs are rarely upset by "combat betrayals", ie ambushes, lures and traps - they expect those. That's just good tactics, and doesn't color their opinion of negotiations and roleplay.

However, if the situation develops via roleplay, then they can get upset by it, if they're not given fair grounds to understand what's going on and "fix" it.

Sounds like your team was up to snuff and caught on that something was wrong with the situation, if not the exact details. Fun!