After an intro set in Belfast in 1973, Shadow Dancer flashes forward 20 years, shifting its action to London and delivering a set piece of imposing skill and power. In nearly wordless fashion, director James Marsh follows a young woman as she boards a train, exits at a Tube station where she drops a suspicious package on the steps, and, sensing danger, sneaks off into a tunnel where she makes her escape from the station, only to be immediately picked up by two MI5 agents. Apart from the obvious suspense which Marsh builds gradually, nearly imperceptibly, the sequence effectively sets a mood of paranoia and dissociation, achieved largely through a purposeful employment of blurred backgrounds and off-kilter shots that turn train commuters into alienated, vaguely sinister presences, even as they go about their mundane business.
If nothing else in the film can quite match the bravura execution of this early sequence, Marsh carries forward the mood and menace of the opening into the balance of the work, perfectly matching his aesthetic strategies to the story's shifting moral terrain. For this tale of divided loyalties set in the waning days of the Troubles in Northern Ireland, Marsh keeps the central players' motivations tantalizingly uncertain, letting us in just enough to allow the film to pack its expected emotional punch, while never forcing reductive readings of character and action.
The chief players in the film's complex political-is-personal narrative are Colette McVeigh (Andrea Riseborough), the woman behind the botched subway bombing and a member, along with her brothers, of the IRA, and MI5 agent Mac (Clive Owen), who offers her and her young son protection in exchange for her turning state's evidence. Colette temporarily accepts the offer, only to miss a key meeting with Mac, but eventually gets at least partially on board. Mac's own position becomes increasingly untenable as he butts heads with higher ups over the handling of Colette, who his superiors see as largely disposable, as well as his discovery of a secret file, labeled "Shadow Dancer," that holds the key to the history of the McVeigh family's involvement with the British government.
Acting beneath masks of studied illegibility, both Riseborough and Owen convey the stoical exteriors their characters have spent years building up as part of their jobs. But both also allow a measure of concern to leak through the surface, reaching a culmination in an aborted attempt at fleeting romance between Colette and Mac. The film wisely drops the potential lovers angle, but makes clear Mac's legitimate concern for his charge as well as Colette's own worries about the fate of her young son.
Beyond these constants, though, the film is a web of shifting loyalties in which the characters' allegiance to family, cause, and country is always relative. It's easy enough for a film to sketch out a fraught situation and then imbue it with facile moral ambiguities, but Marsh's treatment of his material never registers as schematic. By keeping us at an appropriate distance from his characters' thoughts, the film may frustrate the sort of identification we expect from more modest politically charged thrillers, and in turn render its final plot twist a bit less striking than puzzling. But thanks to Marsh's uncanny knack for conveying free-floating dread, Shadow Dancer expertly posits a world where politics perpetually corrodes personal connections and paranoia is no more or less than a daily fact of life.