"Masterpiece Mystery: Foyle's War" (PBS, Sundays). Back from an offscreen America after three years in your time but only one in his, Michael Kitchen's great detective begins a seventh season (or eighth, depending on whether you're doing the U.K. or U.S. math), made possible by Acorn Media (distributor of recent and ancient British television by video and by stream) coming on as a co-producer. Where the original series found Foyle untangling various strands of human fecklessness in World War II Hastings, down by the sea, the new series posts him to London and the postwar, Cold War era, where he is impressed into service by MI5 as a kind of in-house detective, helping to sort out things they are otherwise too thick or elevated to notice. As before, the obvious enemy is not the only enemy -- the show was always about the canker on the rose, and the series maintains its historical conscience (which serves also to indict the present). Honeysuckle Weeks is here, too, as driver-assistant Samantha Stewart -- with all respect to Kitchen, it would not quite be "Foyle's War" without her -- whose husband is running for Parliament, or "standing," as they call it there, which says something about something. Kitchen is the sort of detective hero Americans were more used to once -- not young, not buff, not crazy. He doesn't waste words -- as much as a catchphrase as he can muster is to preface a sentence with "Well" (which does, oddly, work as a kind of catchphrase) -- or suffer fools gladly. (He dispatches them with a wit so dry as to be indistinguishable from simple declaration.) There is a moral intensity to Foyle that Kitchen expresses by the slightest raising of his voice or quickening of his words or birdlike cocking of his head. (He also tends to break up his sentences, in the Shatner way, minus the gasping drama.) Like other great detectives of fiction, he is superhumanly observant, adept at spotting the overlooked detail and seeing a puzzle where everyone else just sees a picture. But there is nothing flashy in any of it, which makes him all the more attractive.