"So elusive were they that there was only one way to catch a unicorn . . . Well, in fact there were two.
". . . When it came to the white unicorn, however, only one method stood any chance of success. It required a maiden of unspotted virtue, and six foot of stout hemp rope. The rope was usually no problem.
". . .As time passed, however, times also changed; and although unicorns are by no means common, there are other species rarer and more elusive still. Thus there is only one sure-fire way of catching a maiden of unspotted virtue. It requires a unicorn and six feet of rope."
-- Tom Holt, Grailblazers