Step by step he had moved on the narrowing path that ended in a cul de sac.
We have at last got your Mr. Washington in a cul de sac from which he cannot escape.
When you get up to the picture, you find the cul de sac is an illusion.
It was narrow and steep, and before long ended in a cul de sac.
Had it taken him five years to discover that her mind was a cul de sac?