I don't have to tell you what it's about - I mean, just look at the cover. I can't explain my fascination with Marilyn fiction; just this year I read The Blonde by Anna Godberson (a similar story) but I didn't enjoy that one as much as Korda's book. Godberson twisted the JFK/Marilyn legend to introduce Soviet involvement and to portray MM as a spy. Immortals is flat out Hollywood and gossip and the Mafia - James Ellroy lite.
There's sex in the book, most of it summarized, but you definitely know at least two Kennedy men have a reason to grin silly. The story switches POV to suit the story's progression, with the only first person view belonging to the fictional David Lehman, a PR expert supposedly with many clients in different industries, yet he only seems to work for Joe Kennedy, Sr. and his boys. He's kind of like Nick Carraway in Gatsby, always around and witnessing everything. He's the fixer, arranging meetings and liaisons and tête-à-têtes and...well, you get it. Immortals covers the era from the mid-50s (Marilyn films Seven Year Itch and married to DiMaggio) to her death in 1962. Korda doesn't stray too far from the standard picture of Marilyn, presenting her as perpetually drinking, drugging, and befuddled. The Kennedys are horny yet cold, ambitious yet at the same time tired of paying the price of power. Toward the end you genuinely feel sorry for the lady.
I think the only thing I didn't like about the book was the ending. The story doesn't really end until all three are gone, and there are scenes where villainous forces plot JFK's assassination. Korda could at least have seen the readers through that. Anyway, I've read so many Marilyn books that make her story look boring - this one kept me up at night.