In broad daylight, a man runs at full speed across the Town Hall Square wearing a dress and white. People stare in amazement as he tries to grab a seat in a phone box to make a call. However, his story is even more incredible than they can imagine.

哥本哈根的深夜街頭，一宗宗詭異的謀殺案讓市民人心惶惶，根據證人表示，每次謀殺案發生之前，總會聽到奇妙優美的詠歎調歌聲，警方也因此鎖定女歌手為主要嫌犯，直到女伶的魔術師前夫突然出現，一切才開始水落石出…。丹麥首部結合黑色電影與驚悚類型的影片，1944年問世時，掀起了一陣懸疑旋風，《看誰在尖叫》丹麥導演歐波奈戴爾更宣稱受本片影響極深。