Chasing cats in Kings Landing

Firstly I must commend you on the level of detail found in the linework. There's so much going on it's wonderful.

However there are a couple of things that bother me a little.

The first is, you have chosen to add tonality to your work, and through the excessive use of gray it appears to me like this piece is set at night, however I find that you could have pushed the shadow even more. In chosing to use tone you've added another dimension, atmosphere, but it seems like you didn't give as much attention to the atmosphere as you did to the scene itself. I would suggest adding perhaps another darker gray (if not black) in the really dark corners to really add depth to the piece, I find at the moment the depth is a little lacking, for example the figure should feel closer than the furthest tower, and while the size shows this, I think this should be a consideration across shading also.

And secondly kind of linking in to the previous comment, I find there's a lack of composition across the piece. I gather from this being a fanart of a book that this is an illustrative work. A key in illustration is making clear (but not screaming) what you want this picture to say. After further looking it seems like the characters should be playing an important role in this scene, but they have been relegated to an insignificant place, in favour of an intricate drawing of a castle.
To read this drawing at the moment, I see that you are much more intregued and interested by the forms of the castle than by the emotions and story of the characters (which may not be a bad thing, but then you should perhaps consider the necessity of adding characters at all)

I feel that the characters should be in a much more key position compositionally, cutting off their feet does not aid the storytelling as they are small figures anyway.

Remember in an illustration the first key is communication, does the audience understand what's going on easily from the drawing alone? do they know who the characters are without having to be told?

Naturally I have been exceedingly nitpicky here picking upon 2 of the negative issues of the drawing.
I utterly adore the cat, and how the buildings frame the image giving the illusion that we are viewing from inside a narrow alleyway, outside the castle but there is still a sprawling city outside the walls. I feel your location work, and architectural illustration about this place is very astute and informative, only your communication using the human form as a tool for storytelling could do with some experimentation <img src="e.deviantart.net/emoticons/b/b…" width="15" height="15" alt="" title=" (Big Grin)" /> I think if you were to nail that, along with your background work, you could be on the way to creating some very formidable illustrations.