The elemental investigative couple find themselves in a building apparently haunted by the spirits of children who have been summoned from old photographs by a featureless entity who is powerful enough to be a real threat to the usually unflappable agents. After the pure sci-fi of assignment 3, this series returns to the show's earlier feel of closed-in supernatural horror with a vague 'rational' underpinning. The villain, in all his/its manifestations, is quite good (you need to be a bit forgiving about the makeup, given the show's budget) and the central premise, the blending of the reality of the present with that of the photographed past, is intriguing. Unfortunately, the end is a bit of a contrived letdown. At four only episodes, this assignment moves along quickly and is generally a good entry in the strange, cryptic quasi-sci-fi-fantasy series.