After four years, Wallander is back for one more stand, though it could become difficult for him.

Kenneth Branagh’s fourth and last round as the late novelist Henning Mankell’s Swedish sleuth begins Sunday (May 8), as PBS’ “Masterpiece Mystery!” launches the three-episode “Wallander, The Final Season.” However, Inspector Kurt Wallander may be in no condition to finish the perilous cases that start in South Africa with “The White Lioness,” since the challenges of age –- and possibly something else, perhaps the Alzheimer’s disease that afflicted his father –- cause a professional carelessness that leaves him in a very uncertain state.

“The ‘Wallander’ books, when I first encountered them, were ones that I read purely for pleasure,” Emmy winner Branagh, also a “Wallander” executive producer and a noted director (“Cinderella,” “Thor”), tells Zap2it.

“In my business sometimes, if you’re lucky and you’re busy, you end up doing a lot of reading that can sometimes be a little low on sheer freedom and joy and enjoyment. These books were ones that I took my time to read, but I read them all sort of within a number of months. [The television version] sort of resists binge-viewing in a way, though maybe people do it that way, and that’s fine.”

The last two episodes, “A Lesson in Love” (May 15) and “The Troubled Man” (May 22), bring Wallander back to Sweden and also feature fellow returnees Jeany Spark (as Wallander’s daughter) and Richard McCabe. Along the way, Branagh’s performance is marked by stretches of silence, which he feels owes to the Swedish environment where the residents “seem to have a wonderful poker face and ability to listen.

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“To go there was to be part of that atmosphere, and for it to be something that was part of what you did naturally … and yet, it can’t merely be a style or a mannerism. If you’re thinking about something, you’re thinking about something because it’s real. And there, the encouragement in the very air itself is to do that, so to play it as an actor was natural, challenging and exciting.”

Portraying Wallander’s memory lapses, which extend at one point to the sleuth leaving his gun behind, posed a new and special challenge for Branagh: “It was trying to make things as specific as possible, and to try and work out what would be particularly frustrating for a man like Wallander, who has to face the fact that his own particular isolationism — he’s rather a separate kind of individual — makes things pretty tricky if you are starting to become forgetful.

“If you are especially disposed to not share intimate details with your family, then I think the chance of being separate and isolated and paranoid happens very quickly … in addition to the practicalities of what can happen when you are losing a sense of who you are, where you have been, and who those are around you are.”

With the new “Wallander” stories clearly labeled as “The Final Season,” Branagh says reviving the character later would have been up to writer Mankell, who died last year. In closing out the part, the performer notes his appreciation of Wallander being “incapable of any sort of small talk or phoniness. It meant he was just sort of almost too intense for everything: his life, his job, etc. That meant that as an actor, you had to really sort of strip things down.

“And I found that helpful, challenging and difficult,” Branagh adds. “And I miss it, because it’s really a very bracing and rigorous way of doing your work.”

Posted by:Jay Bobbin