The second shot, especially, is certainly well-rendered … but ooh, is it dark. It’s going to be very hard to light some action in a space like that. As soon as your protagonist goes in there, s/he’s going to disappear. You’ll have an under-exposed picture: murky, not spooky.
The effect of darkness in a scene is actually achieved by use of contrast. The “black” areas that you are looking at on your monitor right now are really no “darker” than the screen would be if you switched the monitor off right now… if you did that, it would appear to “lighten” considerably. What makes it dark is the bright areas near to it, and by the sharp delineation of contrast (versus a gradual one).
So, when you put actors in here, you’re going to need to be able to illuminate them properly … and when you do so, of course, the surrounding areas will seem darker than they do on the “empty set.” It might be good to start plotting their movement-paths through the set now, while you are still rigging the lights, so that you can get “spooky darkness” and proper illumination at the same time. Even if the character’s going to be carrying a practical light (e.g. a torch), most of the lighting will still need to come from the environment.