<P> The title of the book comes from Act 4 , Scene 1 of William Shakespeare 's Macbeth , when the second witch says : </P>
<P> The title of the book comes from Act 4 , Scene 1 of William Shakespeare 's Macbeth , when the second witch says : </P>
who says by the pricking of my thumbs
who says by the pricking of my thumbs
the second witch
the second witch