Destiny Times Three by Fritz Leiber

He who lets fortunetellers shape his decisions, follows a chartless course. Artemidorus of Cilicia

Alternate waves of guilt and almost unbearable excitement washed Clawly I as he hurried through the deserted corridors of the Blue Lorraine toward the office of Oktav. In grimmest seriousness he wondered whether his own fancied role of mad Pied Piper had not come true, whether his mind -- and those of Firemoor and his other accomplices in the Martian hoax -- were not already more than half usurped by diabolically mischievous mentalities whose only purpose, or pleasure, was to see a sane world reduced to chaos.