The real mystery surrounding this terrific cop yarn is why hasn't it become better known in the United States, taking its rightful place alongside other fine British exports such as "Midsomer Murders," "New Tricks," "Scott and Bailey" and "Luther"? The shame of it is, this may be the best of the lot. The heart of the series is David Jason as detective Jack Frost. Jason's Frost is a complex Everyman who has a real past, and a very human and messy one at that, which seeps into his job in very believable and completely non-melodramatic ways. He absorbs as much punishment as he dishes out, gets quiet when you would expect him to roar, roars when when you think he might calm down. In a word, Jason makes this character fascinating and always believable. The performance seems to have a profound and happy effect on the rest of the cast, regulars as well as guest stars (and wow, do they have great ones, many whom you've seen in films and other favorite series). The love of creating something special, together, is palpable and a joy to watch. The production values and cinematography soar, on a level with any good motion picture. But aside from Jason's Frost, the other star of the series is the writing. There are always two plots working simultaneously, two cases. Sometimes they merge, but not always, and come to think of it, not that often. This plot device keeps the viewer guessing _ and focused. What's most fascinating, however, is that the cases aren't always solved, the characters don't always survive and the endings aren't always happy. Or, sometimes, one case is solved and all is well while the other goes haywire. And sometimes there is a carryover of character or plot. You just never know. And therein lies the genius of this series. The unpredictability. The quality is always tops _ that, you can depend on. Hopefully, someone will make "A Touch of Frost" more readily available in America, where it will undoubtedly fly off the shelves. Until then, it's worth tracking down. Just prepare to become addicted. It's that good.