Rev. Joe -- Gnostics

I read a few books on the Gnostic movement and reading a book (starts mainly mid-2nd Century) from the 1980s that expands things to the middle ages and the modern day (it was a companion to a British t.v. series). It starts okay but gets to be a trudge. Also, repeatedly, a complete account is strangely not provided in many books. A bit more on pre-Jesus Hellenistic/Jewish thought would be useful -- Ehrman in one book briefly covers the matter.