I remember reading that book many years ago. Alas, I can't remember anything about it now.
They have special meaning to me since Keith Emerson, keyboards player in my favourite 1970s rock band, Emerson, Lake and Palmer, wrote a piece in three parts called The Three Fates - the parts being called, of course, Clotho, Lachesis and Atropos. It appeared on their first album.
It has been years since I read the Immoralites series by Pier, but I do remember bits and pieces of the books. Emerson, Lake and Palmer...Ah yes...I remember them and the score