Franzen's strength has always been realism. I've read both The Corrections and Freedom, and while they were not the most exciting novels, they kept me going until the end because I felt I was inside those peoples' lives and heads, and it was all so real. The trouble is that realism can be boring.Purity is never boring. It does stretch plausibility at times, but it's more exiting than his previous novels. I had the impression that after Freedom, Franzen might have read Larsson's The Girl With the Dragon Tattoo, and admired the protagonist Lisbeth. Maybe he thought "I want a main character a little bit like that". Franzen's Pip is a little bit like Lisbeth: she's smart, hostile, bitchy, and socially awkward. She's a fascinating main character.The plot of Purity is less linear that Franzen's previous books. It has the structure of a series of novellas, set in different times and places (contemporary activists in Oakland, CA, communist East Germany, a Bolivian jungle camp, etc). I love this style of novel. Maybe Franzen read David Mitchell's Cloud Atlas, and thought "I want a plot a little bit like that".Some reviewers have noted (or complained) that Purity is a BIG novel. It is big, but did not feel bloated or oversize to me. Part of the reason for Purity's size is that Franzen, in the psychoanalytical tradition tells the story not just of Pip, but also of her parents and her grandparents, at length. He likes childhood determination. By giving us all this background, we get the complete personality of the protagonist. But of course the plot is not limited to family. There are peripheral tales, every one vividly drawn. But you might find it distracting. I loved all of it.What Franzen gave us in Purity is not a roller coaster of a book. But it does sway more than a standard deviation from the mean of realism. It kept me enthralled from the first page until the last.