A young woman's death at a munitions factory appears to be an accident, until another woman is murdered.

A young woman is found dead at a munitions factory; Foyle suspects her death is an industrial accident. But when another woman - Sergeant Milner's estranged wife, Jane - is brutally murdered in town, he begins to suspect that the two deaths are linked. When Milner emerges as the prime suspect, Foyle and Sam must step up the investigation to prove his innocence.