This paper looks at the rationale and operation of the death penalty and the prerogative of mercy in respect of female offenders convicted of a capital offence in Australia during the early colonial period from 1824 to 1860, through a consideration of the case of Sarah McGregor and Mary Maloney in 1834. McGregor and Maloney were assigned convict servants, convicted and condemned to death for the murder of their master, a Captain Waldron, a crime that was truly ‘beyond the pale’ in early colonial society. Yet after a spirited campaign, both women were reprieved. Although punishment and deterrence were themes strongly manifest in the exercise of the death penalty, this paper argues these were not the sole or even paramount considerations. The colonial authorities, even in relation to the apparent worst of offenders such as McGregor and Maloney, took seriously the exercise of mercy and, as far as possible, allowed mercy to season justice. Yet despite this humanity, female capital offenders were seen in stark and polarised terms, ‘All that's good and virtuous, or that they are depraved and abandoned in the extreme?’ Female offenders perceived to fall into the former category could expect sympathy and the likelihood of reprieve, while those perceived to fall into the latter category had little hope of mercy, and could expect to receive the ‘ultimate penalty of the law’. The case of Maloney and McGregor illustrates the arbitrariness of this polarised stigma attached to female offenders. Yet despite the nature and gravity of their crime, ‘justice was due even to them.’ Maloney and McGregor underwent a remarkable transformation from apparent ‘criminals of the deepest dye’ to figures deserving of compassion and ultimately of the grant of mercy.