Interesting picture. It has loads of potential. Here's my 2pence worth: Without adding more textures, I advise working on the lighting. If this is an evening rescue, strengthen the shadows of the background and use with a bit of "moonlight" or a torch for the light source. If this is a day time rescue, crank up the light so the shadows are noticably connected to the figures. Right now, everything seems to be floating in space. Either way, on your leading light, crank your "map size" dial up to at least 1024, though 2000-4000 is better. Then set your "shadow" dial to .25 to .5. Set all other lights to "no shadow".