Set in Canada, this compelling WW II actioner presents the dashing Errol Flynn in the role of a traitor . . . or at least that's what he appears to be through much of the film. When Steve Wagner (Flynn), a Mountie with German-born parents, learns that the man he has rescued is a German spy, he reveals his sympathies for the Fatherland and sets out to help Col. von Keller (Helmut Dantine) complete his mission. The German remains skeptical, however, and demands that Wagner bring along girl friend Laura McBain (Julie Bishop) as a kind of hostage. Wagner then proceeds to lead von Keller and several other German agents to the site of their rendezvous with a bomber that will strike select targets they have identified. But with the mission on the brink of successful completion, what better time for Wagner to show his true colors? Flynn, who had been rejected by every branch of the military because of a multitude of physical problems, collapsed during the making of this fast-paced film, the result of a bout with tuberculosis. NORTHERN PURSUIT, for all its comic-book heroics, is nevertheless entertaining and expertly directed by action helmsman Raoul Walsh. The great swashbuckler Flynn had lost none of his dash, Bishop is alluring, and Dantine is properly repulsive as the heavy.