They are "Bad To The Bone"... it’s only a matter of time before they become Deadly Women.

An investigation into what made women like Aileen Wuornos, Anna Hahn and Dorothea Puente stalk the night in search of victims.

A woman boards a train with a grisly secret in her luggage, an active imagination causes a gruesome crime, and a seductress moves from men to murder.

For an English Rose, husbands equal dollar signs; for a serial killer, feeding her family pays; for a businesswoman, a missing mother keeps the checks coming.

When these women have scores to settle, they take matters into their own hands. A traumatized woman thinks she's an avenging angel; one of Mexico's infamous serial killers targets the elderly; and a man is butchered by two women he tries to help.

The case of 17th-century serial killer Erzsebet Bathory - a Hungarian aristocrat who is said to have murdered 600 of her servants in an attempt to achieve eternal youth

The cases of Belle Gunness, who murdered her victims to reap financial rewards, and a carer from Connecticut who turned a home for the elderly into a death parlour

The stories of notorious killer Katherine Knight, an Australian who skinned and decapitated her errant lover, and Blanche Taylor-Moore, who poisoned her partner in hospital

Connecting three women who were driven by different reasons to commit murder.

The case of two women who murdered their own children because of an obsessive infatuation.

How Judi Beunoano and Genene Jones managed to keep the crimes they committed a secret.

Examining the cases involving 'angels of death', including the crimes of Beverley Allitt and Stella Nickell.

The case of 10-year-old Mary Bell who strangled toddlers, a playground plot that ended in murder and a teenage passion that turned to bloody rage.

A businesswoman kills for cash, a bizarre love affair ends in slaughter, and a midwife becomes a cold-blooded murderer.

The crimes of psychopathic killers, including a nurse who betrayed a patient's trust to indulge her deadly desires, and a brutal babysitter.

Looking at killers who hid their instability, including an outgoing hiding dark secrets at home, and two old ladies behind a horrific murder.

Examining crimes of passion, including an office affair that turned toxic and a lover who used the Internet as a murder weapon.

How Charles Manson drove women to murder, exploring Myra Hindley's past, and why a young mother was persuaded to kill.

How a woman took a baby from an expectant mother's womb, two girls killed to protect their friendship, and a killer committed her crimes for a serial murderer she loved.

A sex-obsessed housewife who lured girls to their graves, a couple who took pleasure in killing, and a woman who swapped single motherhood for a violent relationship.

A mother who smothered her baby, a woman who drowned the sons she believed made her unhappy, and how another who was driven by delusions to destroy her family.

A promiscuous housewife who murdered her husband, a woman who tortured her lodger to death, and a police officer who took a child on a killing spree.

A wronged wife who murdered her ex-husband, a jealous girlfriend who took revenge on her rival, and a girl who killed her own father.

A mother who manipulated her son into committing murder, a woman who made a deadly request of her children, and a daughter who was used as a lure for a family business.

The path towards revenge can sometimes lead to murder. It can be quick,fiery and violent. When these women were crossed, they didn't take it lying down. Murder was their answer.