The exercise of the death penalty in England in the 19th century has long been a subject of academic scrutiny and popular interest. Scholars have also studied the role and importance of the prerogative of mercy in the context of the capital sanction. The exercise of both the death penalty and the prerogative of mercy, in comparison, in colonial Australia have been often overlooked. This article, which is part of a wider ongoing study, considers the rationale and operation of the prerogative of mercy in colonial Australia during the period 1824 to 1860. The focus is on those convicted of a capital offence in the Australian colonies, particularly convicts already serving a sentence for previous offences, and who, indeed, might also be a previous recipient of a pardon. The article considers the question of secondary punishment and the grant of mercy in respect of three notable incidences of mutiny and piracy at Norfolk Island in 1827, 1834 and 1842. This article argues that whilst there was manifest a strong theme of punishment and deterrence in the exercise of the death penalty, these were not the sole or even paramount considerations. Rather it is argued that the colonial authorities, even in relation to those offenders who were “beyond the pale” such as the Norfolk Island mutineers, took seriously the exercise of mercy in the context of emerging self-government. The implementation of the death penalty was not randomly administered, but was considered within the operation of the rule of law, where, as far as possible, even in respect of offenders of the “deepest dye,” “mercy seasons justice.”