Around each city there is an unseen wall of force.

She pointed to the unseen walls of the crater.

Trapped behind the unseen wall, she was forced to watch helplessly.

It hit the unseen wall of the circle and bounced back to clatter at my feet.

Dyessa glanced back up the canyon, toward the unseen wall of stone and rubble behind her.

At the crack of the shot the giant head jerked backward as if the monster had run into an unseen wall.

Twill take more than a wall unseen to best me.

They formed an unseen wall to penetrate it would set off alarms.

I commanded, slashing at that unseen wall with the sword I'd just made.

Frantically he beat upon the unseen wall that blocked his path.