'Restless' on Sundance Channel is a spy story with a stiff upper lip For a nation bewitched by period dramas in which men wear hats and sip whiskey while making eyes at crimson-lipped women who smoke an endless succession of unfiltered cigarettes, the Sundance Channel miniseries "Restless" offers all that and more. Adapted by William Boyd from his novel of the same name, the miniseries, which premieres Friday, centers on a secret British intelligence agency attempting to draw the reluctant United States into World War II. Which means in addition to the fabulous clothes, there's a fabulous British cast, not to mention the endlessly fascinating world of espionage and a bit of revelatory World War II history. Oh, and if that weren't enough, it stars Michelle Dockery, enjoying PBS iconic status for her portrayal of Lady Mary in "Downton Abbey." Here, Dockery plays Ruth Gilmartin, a single mother and modern woman - or modern-ish, as the action begins in the 1970s. During an obligatory daughterly visit, Ruth's mother, Sally (Charlotte Rampling), expresses a seemingly paranoid concern that she is being watched. When Ruth matter-of-factly, if not kindly, suggests she see a doctor, Sally levels her daughter with a Ramplingesque look and hands her a dossier that reveals Sally's true past. Far from being Ruth's plain old British mother, Sally is really a native Russian who, after her brother was killed by fascists in the early '40s, was drafted by British intelligence and trained as a spy. As Ruth begins to read her mother's story, the narrative goes into flashback where we meet the young Eva Delectorskaya, played by Hayley Atwell. After swallowing the major inconsistency so often accompanying such past/present roles - Atwell's eyes are brown, Rampling's hypnotically blue - it's easy to get swept up in Eva's tale. Seduced (first professionally and then literally) by Lucas Romer (Rufus Sewell), who puts her through spy training at a Downton-like estate, Eva takes to her new life with alacrity, even though the missions we see her undertake often go horribly wrong. Ruth, meanwhile, is trying to come to terms with a mother she apparently never really knew - "none of us really knows anyone," Sally tells her at one point, "even those closest to us" - though any woman who looks like Rampling clearly has a past worth knowing. Sally is convinced that someone from that past has found her, with murderous intent. As the wartime narrative unfolds to reveal the events that might put Sally's life in danger 30 years later, Ruth struggles to believe. Co-produced by Sundance and the BBC, it's a very British story, a dimly lighted labyrinth of clipped sentences, meaningful glances and sudden bursts of passion rather than rock 'em, sock 'em car chases and gunplay. The work Eva and her compatriots are doing consists mostly of introducing false intelligence into the foreign press in the hopes of confusing the Germans and, later, persuading the United States to come to the aid of the Allied forces. So there are no Nikita-like acrobatics, which would have only split Eva's skirt anyway. The subtle nature of the action makes the pace a bit slow at times, but since we all know that something will eventually cause Eva to ditch her ties to the British government and her identity, even the most staid scenes contain possible clues to the future. In both time frames, the period is richly evoked, and the performances are universally fine. Rather than go full-bore feisty, Atwell's Eva is a delicate mixture of fear and resolve; each time she manages to extricate herself from a bad situation, we see the palsied aftermath of relief, disbelief and delight. Sewell is an actor born to seduce, and Dockery proves that her brand of slender steeliness plays just as well in bell bottoms as in evening gowns. Even in such splendid company, though, Rampling is a beacon, radiating a carefully contained and riveting vitality. When, in the second episode, we finally meet the older Lucas, played by Michael Gambon, it's difficult not to wish that the scene would never end. Real passion, we are reminded, is not the province of young lovers; it's something much more complicated and dangerous than that, and despite our best efforts, it cannot remain hidden. Where: Sundance When: 9 p.m. Friday Rating: TV-14-LV (may be unsuitable for children under the age of 14 with advisories for coarse language and violence)