In his new novel, "Indignation," Philip Roth withholds a crucial piece of information — and that's an understatement — until about a quarter of the way through. This placement seems to me right on the borderline of fair game for reviewers, and not to tell it would misrepresent the book. (A more alert reader than I was might figure it out simply by looking at the table of contents.) Still, it seems mean to spoil a strategic surprise for folks who like that kind of thing. So in case you want to head for the exit now, I'm going to vamp for a couple of paragraphs of harmless generalities and evasive plot summary before getting specific. Roth has a couple more surprises, too (which you might see coming but probably won't), and I promise not to get anywhere near those. Anyhow, isn't it surprising enough that Roth, now 75, has just published his third novel in three years?