Driving home on the interstate, only billboards keep us from reentering the black-&-white world of a movie set in 1943. They beckon like lit windows in a whorehouse of dreams. We are adding up the clues & concluding that we lacked sufficient information to have known who did it or why, but perhaps it was better that way. The conventional presumption of entirely solvable mysteries, though essential to the genre, breeds false expectations about outcomes in what we like to think of as the real world. In this movie, the buzzbombs can die and drop anywhere; people turn pale as hospital gowns when they hear the buzzing stop. The droll & self-regarding inspector wields a folded umbrella like the idea of a weapon, & fails as much as he succeeds. None of the characters are wholly likeable: in this way, too, the film imitates real life, or at least the shadow-side of it. Ironically, though, it’s the abundant & dramatic shadows in the night scenes that stretch credulity, since the sources of light that cast them are, as usual in the movies, unseen & improbable. The green danger of the title concerns the breath, or lack of it, which we can assess by watching a leather bladder beside the operating table expand & contract. As for colors, green or otherwise, we are of course forced to take their word for it. From such flawed clues we deduce far more than we ought to, & allow ourselves briefly to believe in these frail people, in this fatal time.