Ooh, a murder mystery in the wilds of 15th century Scotland! That got my hopes up. We're the illegitimate son of the local Warden -- that is, the guy who pretty much handles questions of justice in these lands -- and we're supposed to go around asking questions to figure out the truth of what's going on after a minor laird of gets butchered on his doorstep and his widow blames a rival clan.
This could be so awesome. But ... it seems as though we're not really given enough to work on, here. The available conversation topics seem very limited, and the responses don't give us very much. We're told, for instance, that there were lights and strange noises on the night of the murder, but we can't ask for any further details. We can't ask about the murdered man or about his personal relations with other people. We can't ask about the individual suspects -- it's as though opinions about the clans as a whole suffice as opinions about their representatives.
And there's the other problem. Opinions do not constitute hard evidence. We can get an idea of how the clan alliances map out from speaking to everyone, but that's about it. Later on, when we actually find something that constitutes evidence ... it looks as though our clue is a facial reaction from the guilty party when we show it to them? That manages to be both heavy-handed and inconclusive at once.
The main issue here, I think, is that the story needs more development. The various characters need to be developed as personalities and considered as human beings. I think that simply drawing up different responses about the individual characters can help flesh them out more and make them stand out -- as a writer, you learn a lot more about your characters when you find yourself forced to write up what each character thinks about every other character. The finale currently comes off as a deus-ex-machina, and needs to be rethought: the idea of being held at knifepoint by an assassin who wants to know if you've guessed right feels pretty unbelievable, but the basic idea of having to cough up your answer under duress has potential. In spite of everything, the basic plot of the story is actually pretty good.
As a breakfast, it's a pair of very runny soft-boiled eggs and a bowl full of dry oats. You can see where this is going, but it'll need a lot more time in the kitchen before it gets there.