You a Wallander fan? Me too. I’ve most of Henning Mankell’s books, love the TV series with the brilliant Krister Henriksson, even dig the Kenneth Brannagh version with its different feel, and have checked out the older film versions with the splendid Rolf Lassgård in the title role and love them too.

But sometimes when Henning moves into other crime territory he doesn’t quite pull it off. My biggest disappointment was Kennedy’s Brain. Don’t read the rest of this blog post if you want to avoid big spoilers.

Originally published 10 years ago, the book could have been a great mystery with a hard political edge, yet it doesn’t gel together.

Here’s the basic plot. Swedish archaeologist Louise Cantor returns home from an excavation in Greece and discovers her son is dead in his flat. She refuses to believe that it’s suicide, and sets off on a search for answers. The initial analogies between archaeology and trying to piece together what happened to her dead son are interesting. Yet many things don’t add up.

The characters aren’t a patch on the Wallander series. Some are downright implausible. Take Louise’s father. She is 54. So he must be, well, at least 20 years older I guess. Mid seventies, maybe even in his eighties. Yet he never sleeps and carries her in his arms when she collapses – a pensioner superman.

Her ex husband is strangled in the middle of Barcelona. Why? And she doesn’t get word of the autopsy through official channels in Spain or Sweden, even though she has reported him missing. No officials contact her. Again, why?

I got jetlag from the amount of air travel: Greece, Sweden, Spain, Australia, South Africa, Mozambique and so on. That may look good on TV but even James Bond and Michael O’Leary don’t do that many air miles in a month.

And never a problem with visas when she buys air tickets – usually on the spur of the moment – to opposite ends of the globe. Then there’s the money. So much of it. She is attacked, people are killed sitting next to her etc etc etc, yet nobody – not even Customs or airport security – notices the large stash of cash on her.

Perhaps the TV adaptation (it’s mostly in German) is better. It even has Rolf Lassgård in a minor role – and Michael Nyqvist from the Stieg Larsson films.

But what about “Kennedy’s Brain” itself? Did the marketing department and a literary agent come up with this title after one too many pints?

It may latch onto longstanding obsessions with the Kennedy assassination but it feels bolted on, a fleeting metaphor with no proper organic link to what’s going on. Or maybe that’s Kennedy’s brain in the baddie’s desk all along? As if.

Mankell’s books often tackle big political issues, from pharma empires to AIDS. He frequently delves deep into racism or into underdevelopment in Africa, and he has championed many causes of oppressed peoples.

But the overall plot here is too much in the same territory as John le Carré’s The Constant Gardener, and the execution lags a long way behind it (and the film version of le Carré’s book). The ending is also loose, mostly unresolved and very dissatisfying.

Don’t get me wrong. I’ll keep reading Henning Mankell, I’ll keep watching Wallander. But this is far from Mankell at his best.