The fog that drifts around corners, gripping with yellowed fingers that catch at your throat.
Pollution on the march, acid rain, the smell of drains and river mud where things long dead lay waiting. Others not dead enough clutch at the weeds as they pass by sluggish and grey.
Sound crawls fighting to be heard, silence falls, only the cries of wading birds shrill on the shoreline cut a window into the world.
Running footsteps in an alley slip away to some hidden place behind the choking wall, a real 'Pea Souper' covers all.
Trying for atmosphere