An alley usually means a dead end, although not ALL alleys lead to dead ends. If you dream you are on a difficult, and dark corridor which has no alternative branching outlet, then that is probably your situation in life right now. You have to decide if this is the path for you to travel. Otherwise, you have to think of leaving this alley, which is a metaphorical symbol.
Photo prompt from The Daily Spur – corridor/ dead end alley.