Vincent Bugliosi

'Helter-Skelter' was the motive for the murders. Manson borrowed that term from a Beatles song on the 'White Album.' In England, helter-skelter is a playground ride. To Manson, helter-skelter meant a war between whites and blacks that the Beatles were in favor of.

The historical novelist has to consider what has actually happened, while the SF writer is dealing in possibilities, but they are both in the business of imagining a world unlike our own and yet connected to it.