Autumn 1916. The first Zeppelin shot down by a British plane bursts into flames over London and plummets to the ground. As those brave enough to remain outside during the air raid gaze at the spectacular display, a killer takes advantage of their distraction. The following morning a renowned ballroom dancer is found butchered in an alleyway. As Detective Inspector Harvey Marmion and Sergeant Joe Keedy build a picture of the victim's promiscuous lifestyle, the number of suspects multiplies. Will Sergeant Keedy catch the killer before the gruesome nature of the dancer's death gets out and panic spreads?