The Second Episode

    "As for the word CLUE, we are indebted for its genesis to mythology.... Clue has descended etymologically from CLEW (in common with many other words of similar endings; i.e., TREW, BLEW, etc.) ... being a literal Old English translation of the Greek word for thread, directly traceable to the legend of Theseus and Ariadne and the ball of cord she gave him with which to grope his way out of the Labyrinth after killing the Minotaur.... A clue in the detectival sense may be of an intangible as well as a tangible nature; it may be a state of mind as well as a state of fact; or it may derive from the absence of a relevant object as well as from the presence of an irrelevant one.... But always, whatever its nature, a clue is the thread which guides the crime investigator through the labyrinth of nonessential data into the light of complete comprehension...."
    —From William O. Green's
    Introduction to Ars Criminalis
    By John Strang