The voice made no answer. Whizz came a flint, apparently out of the air, and missed Mr. Marvel’s shoulder by a hair’s-breadth. Mr. Marvel, turning, saw a flint jerk up into the air, trace a complicated path, hang for a moment, and then fling at his feet with almost invisible rapidity. He was too amazed to dodge. Whizz it came, and ricochetted from a bare toe into the ditch. Mr. Thomas Marvel jumped a foot and howled aloud. Then he started to run, tripped over an unseen obstacle, and came head over heels into a sitting position.

“ Now ,” said the voice, as a third stone curved upward and hung in the air above the tramp. “Am I imagination?”