After reading Michael Ridpath’s wonderful thrillers set in the financial world, a quarter century ago, I lost track of him until I chanced upon the engaging Launch Code (my review) and then last year’s The Diplomat’s Wife (my review). Now comes “Death in Dalvik,” Book 6 in his Magnus series about an Icelandic murder detective who goes to America and returns as man of hybrid cultures. Entering a series after missing five books can make life tricky but I need not have feared. From the get-go, I knew was in able hands. Magnus is instantly likeable, instantly seen as dogged, intelligent, and moral. The most amazing feature of this outing is that Death in Dalvik, presciently, is all about bitcoins and cryptocurrency, and reaches into the heart of the massive meltdown of all cryptocurrencies unfolding right now. When a nineteen-year-old student from a coastal Icelandic village is gifted a few bitcoin, she in turn passes bitcoin to her mother to save the family farm, and her mother infects the area with cryptocurrency mania. When the mother is savagely murdered. Inspector Magnus Jonson seeks his murderer even as a local cryptocurrency crisis rocks the community. Ridpath is a smooth, adept stylist who brings the strange beauty of Iceland alive. A great strength is a gradual and skillful introduction to the arcane world of cryptocurrencies. The plot rockets along. Death in Dalvik is impressive, reminding me that I must find a beach on which to devour the earlier books.