“How’s J.K. Rowling’s new book?” a colleague asks me, when I am 75 pages in. “It’s OK,” I say. “Though, if you took it away from me now and refused to give it back, I wouldn’t be that bothered.”

The Casual Vacancy, as everyone knows by now, is about the death of a parish councillor and the election that follows. Not that you would know this from the first 75 pages.

Instead, we are introduced to character after character after character. There are so many people to introduce that there is little space left for plot development. On the upside, there may be one or two characters whom you really like. On the downside, you are unlikely to see them again for another 30 or 40 pages.

“How’s J.K. Rowling’s new book?” a couple of friends ask me, when I am 230 pages in. (This question, I am quickly learning, is the inevitable consequence of reading the book within viewing distance of anyone else.)

“Well, it’s OK,” I say. “Though if you took it away from me now and didn’t give it back, I’d get over it pretty quickly.”

Rowling’s strengths are the same as they ever were. Her prose is warm and accessible, if pedestrian. She is very good at depicting the insecurities and internal contradictions of teenagers. And she has a real eye for middle-class pretension: there is a marvellous dinner-party scene, in which she perfectly captures the attendees’ self-absorption and mutual envy.

But I’m almost halfway through, and I’m still not sure where the novel is going.

“Oh, you’re reading J.K. Rowling’s new book!” says the woman next to me on the train, when I am 380 pages in. “How is it?” (This really happened. The Casual Vacancy is the literary equivalent of the Blitz spirit.)

“It’s OK,” I say. “But if you said I wasn’t allowed to read any more, I wouldn’t be devastated.”

Some of the multiple storylines are beginning to come together. And seeing the interior lives of so many characters also conveys the claustrophobia of a small town: “I know her!” you think, when a character has business, school or emotional dealings with another. “What a small world.”

It would be stretching things to say that there are character arcs. But characters are developing, slowly. However, like the middle-class snobs who want to shut down the parish drug clinic, I don’t care enough about the people. Fundamentally, the book is all distraction and detail, and not quite enough emotional heart.

“You’re reading J.K. Rowling’s new book?” a friend says, when I am 450 pages in. “I’ve heard it’s not great.”

“It’s OK, actually,” I say. “I’m on the home stretch. It’s been all right.”