Rites of expiation and reparation (prāyaścitta) may not seem central to the history of the Mantramārga, but they provide a fascinating angle from which to view the evolution of this broad religious tradition. Instead of focussing on the evolution and philosophical defence of Śaiva doctrines, or on the examination of ritual practices and of theories developed to justify and shore up such practices, this study puts the spotlight instead on social dimensions of the religion.