I figured that much out after I ate one of the guys, then asked another what to do next. But I'm curious, if you eat all three, who is left to give you a hint or point you in the right direction? Or do you have to just take a random guess at that point? Because otherwise, it seems you'd be SOL unless you talk to EVERYONE in town and hope for the best.
Does Valeri even have the "password for archives" speech option unless you asked one of the veggies about who to ask?