Ms. Nielsen was also attracted to the play's darker undercurrents.

The play's dark undercurrents do not pass unacknowledged here.

From behind him, running like a dark undercurrent to his words, came the low, moaning sound.

The dark undercurrents of the other, a model marriage, are subtly revealed.

However, there is a dark undercurrent in Betaville that impacts some citizens directly.

And there were other darker undercurrents that had not yet come to the surface.

Of course, there is a dark undercurrent of class struggle here.

There was a dark undercurrent of hostility this time.

"Behind the shoulder-to-shoulder unity, there are dark undercurrents at those companies."