The engine coughed, then caught, and the propeller on the nose began to spin, slowly at first, then gaining speed until it was an almost invisible blur.

Wind turbine blades appear to move slowly from a distance but at close range move so quickly as to appear a nearly invisible blur.

Koudelka's eyes stopped jerking, following some invisible starry blur, and came at last into focus.

They ran with bodies low, tails high, legs an invisible blur.

Another jump-and it became a blur, invisible.

The griffin's wings had long ago become an almost invisible blur.

Thousands of thumb-sized birds: tiny harpoon for a nose, invisible blur of wing behind.

A sprite, taking the form of a nearly invisible blur in the air beside his head, whispered a suggestion to him.

Soon the ground crew was aboard, the propellers an invisible blur.

Climbing swiftly, like an invisible blur in the darkness, Jack Bishop inched out on the limb that pointed toward the attic.