Kenneth Branagh's performance as Swedish cop Kurt Wallander makes it the third time when a famous Swedish movie/television cop gets portrayed by an actor who is not from Sweden/speaking Swedish. The first two are Walter Matthau as Jake Martin (Jake Martin is the americanized version of Martin Beck) in The Laughing Policeman (1973) and Derek Jacobi as Martin Beck in The Man Who Went Up in Smoke (1980).
Wallander's father couldn't understand how he would want to be a policeman. This situation is reflected in the original Swedish series, Wallander (2005), when the highly talented trainee Pontus is plagued for similar reasons by his father, a highly successful lawyer.
Povel clearly has an unusually high IQ. Among other things, it is seen in his dark, biting, witty, and self-depreciating sense of humor. The combination of a high IQ and failing mental faculties make his frustration and anguish understandably intense.
This episode contains two actors who play regular characters in the Marvel Cinematic Universe: Tom Hiddleston (Magnus Martinsson), who plays Loki in the MCU, and Nicholas Hoult (Stefan Fredman), who plays Hank McCoy / Beast. This series's lead actor, Kenneth Branagh (Kurt Wallander) also directed an MCU movie, Thor.
Sarah Smart (Anne-Britt Hoglund) & David Warner (Povel Wallander) also worked together on The Secret of Crickley Hall (2012) as Magda Cribben & Percy Judd respectively.