You recall the first time you dealt with a situation like that. You said “I think it’ssss…”, drawing out the ‘s’ just long enough to make him think you might be moving into “suit”. For just a moment, he looked relieved, and that’s when you said “rank”.
You were right, naturally.
So perhaps that’s the angle here. Try to fake him out one way and see if he reacts. If he were an assassin, then his group would likely have signals to identify each other, if only to stay out of each others’ way. Of course, those signals could be anything. Codewords. A particular style of dress. Possibly even a secret handshake.
But maybe you don’t need the specifics. You know for a fact there are former assassins in the Marshguards. And you also know that the other Marshguards tend to find them unsettling.
So perhaps you just need to look like you might be an assassin, for just a moment. See if that gets a reaction.
But how can you do that?
Wear a hood, hold a knife. Don’t forget to give periodic death-glares at passerbys.
even if he were an assassin, you dont know the first thing about the foreigner’s culture. Doing something random and out of place is bound to get you as much of a reaction as something calculated using your cultures paradigm. Try faking a seizure or acting insane, that’s bound to give you some kind of insight.
I edited this slightly on moving it because originally it jumped from “maybe that’s the angle” to “what if he was an assassin”, which was confusing enough to warrant some clarification on how those ideas fit together. I probably thought along the lines I noted here at the time, but just kind of blended it all into that.
The previous suggestion was from someone who hadn’t been closely following, but it was all I had to work with so this is where I ended up taking it. There are times when suggestions get scarce, and I just deal with that as best I can. Sometimes I’ve even asked people who haven’t read the story at all to just toss something out, even without reading.