> Can you summarize it in one or two paragraphs?
Sure. In one phrase: Stuff happens. :-)
No. IMO, it is a robust attempt to place actually-existing/evolving Marxism in the historical-materialistic framework that Marx and Engels themselves laid out, and doing it all by reference to the glorious/tragic experience of actually-existing socialism. Some of the lines have aged in the almost 35 years since those texts were published. Actually, one may think it is talmudic. But exercises in self-reference can lead to insights and aha moments, not unlike what John Von Neumann meant to allude when he said that, "If one has really technically penetrated a subject, things that previously seemed in complete contrast, might [then appear as] purely mathematical transformations of each other." For the specifics, you'll need to at least browse the text. Hope you read it: