All of his pre-directorial efforts were lost, including Scenens børn (1913), the only motion picture directed by eminent Norwegian playwright and stage director Bjørn Bjørnson.

In 1913, Christensen assumed control of the small, Hellborg-based production company for which he worked, and reorganized it as Dansk-Biograf Kompagnie, making a directorial debut with Det hemmelighedsfulde X (The Mysterious X, 1914), a spy melodrama, with camerawork, cutting, and art direction that was considered revolutionary for the period.

Christensen himself played the main role, as in his second film, Hævnens nat (Blind Justice, 1916), portraying a man wrongly accused of murder.

Between 1918 and 1921, Christensen researched the history of necromancy as background for his next and greatest film, Häxan (The Witches, or Witchcraft Through the Ages, 1922).

[2] A plotless panorama of the history of witchcraft, Häxan utilized visual nudity, gore, and shock value on a level that remains unusual for a silent film.

In 1924, MGM swept through the talent pool at UFA and picked up, among others, Christensen, who departed so quickly that he may not have completed his second feature, Die Frau mit dem schlechten Ruf (The Woman of Ill-Repute, 1925).

Breaking his silence, for the Nordisk Company, he wrote and directed Skilsmissens børn (Children of Divorce, 1939), a social melodrama about generation gap.

However, Damen med de lyse Handsker (The Lady with the Light Gloves, 1942) was a spy thriller that proved an unmitigated disaster on the level of Mockery, and Christensen found himself out of the film business for good.

Long circulating in the 16mm market, it was re-edited into a shorter version in 1967 by a British film maker Antony Balch with an added jazz score and narration by William S. Burroughs.