 The subplot set on Cylon Occupied Caprica with Helo and Boomer was  not originally planned; after being left of Caprica in the mini  series, Helo was supposed to never be seen again: the audience would  be left to assume that he died. Only after seeing the audiences  reaction to Helo did the show producers decide to bring him back,  and introduce another Boomer, and the Cylons experiments in  creating a Cylon/Human Hybrid, which eventually became an integral  part of the Cylon "plan".