Sentence:  "May 1947" EDISON'S CONQUEST OF MARS CHAPTER ONE ""LET US GO TO MARS"" It is impossible that the stupendous events which followed the disastrous invasion of the earth by the Martians should go without record, and circumstances having placed the facts at my disposal, I deem it a duty, both to posterity and to those who were witnesses of and participants in the avenging <WSD>counterstroke</WSD> that the earth dealt back at its ruthless enemy in the heavens, to write down the story in a connected form. 
Meaning of the word marked with <WSD> tags:  A retaliation.