Number Six is one of a new breed of Cylons, indistinguishable in appearance from their human creators.  A mixture of cold intellectual or coquettish sexiness, Six seduced Dr. Gaius Baltar into revealing every aspect humanity’s defense network, to destroy their military capability in a single blow. There have been many versions of Six, but each progressive form seems increasingly spiritual, driven by a firm belief in one god and His divine plan for humans and Cylons. She is portrayed by Tricia Helfer in the Battlestar Galactica TV series.