This is an amazing image. Let me just say that right away because I don't want to taint that with this critique. If you're anything like me then you just want to know what you can do to improve so I'll do my best to offer what doesn't look quite right to me. Though, I have to say that I really had to look closely to see them.
My first impression when I looked at the thumbnail was like a steampunk version of the wizard of oz. I think it was the helm of the guard on the left. When I opened the image, I was very surprised by the quality of the rendering and that it wasn't the wizard of oz or steampunk.
When I look at this image, it captures the emotion that the woman is feeling. You can feel this when you look at her. I believe you captured this moment very, very well. The guard on her right has a smug look on his face like he's proud of his accomplishment and nothing she could say would stop him from arresting her. She seems fragile and helpless both by her pose and expression. This is very well done.
Anatomy: Looks really, really good. My only observation on this point is that the shoulder of the arm the guard is holding (her right) looks a bit high. That's the only thing that doesn't look quite right to me. Though, it could just be my untrained eye.
Values: Your values look a little too uniform on the guard to the left. It's making the guard seem flat and lacking form especially around the waist area. Then, this is the hard part to describe, but it looks like you might have gone too far when rendering bounce light. Her hair, for example, wouldn't be receiving the intensity of the red that it is without sun hitting the guard behind her directly and it doesn't seem to be. Her dress almost seems a little too uniform to me as well. It's very well rendered, but besides the part with the sun, the rest of her dress looks a little too uniform. Like I would expect to see more shadow in her left shoulder area and also her face to bring out the form more. Continuing to the right, the guard holding her seems a little too dark compared to how everything else is rendered so he becomes lost a bit. I almost want to think that he would be receiving as much bounce light from the sun hitting the ground in front of them as she is. I can't offer how to fix that. I would just have to play with the values until it looked right. Continuing a little further to the right, it's like that object in the foreground competes too much with the guard that's holding her. For example, the beam behind the guard holding her, the guard holding her, and the object in the front all seem to have the same dark value which is confusing and lacks depth there.
Composition. Spot on with the framing of the image. Starting from the left. The to men add interest and depth to your story and also aid in leading the viewer to the main interest of the story. The second guys buckle and lines are also pointing in that direction which is good. The guard is looking at your subject which makes the viewer look in that direction and the rest of her fingers fan out to point at the guard and the object he's holding (great job). Also, her right finger forms a line with the light coming down which is great to lead the viewer down into the scene. I almost want to see her left index finger extended a little bit to point at the object the guard is holding to add a little more depth to the story. As if to say, "that's not mine" or "I've never seen that before" or something .
Field of depth: Not much I can offer here. Though, at first glance it looked like the arch in the back was a single arch (no ally between them), but after careful study of your image, found that it's actually an ally or something. It was just a little confusion that I noted. You probably could have gotten away with no ally there and just continue that light beam up.
Texture: Amazing rendering job. Simply amazing.
I'm very impressed by this image and will keep it in my favorites to hope that some day I can obtain the level of excellence that you achieved. I also hope my critique doesn't taint others interpretations and that you simply use it to improve.