During the 1920s-1930s in Iran, a highly unusual development took place in the clerical interpretation of a crucial feature of Sh?‘? doctrine. In the midst of an epoch altering dynastic transition and eventual entrenchment, the reformist theologian Shar?‘at Sangalag? (d.1944) openly expressed and began teaching the denial of the concept of messianic al-raj‘a (return). Not surprisingly, his initiative instigated an uproar among his fellow theologians, several of whom wrote scathing rebuttals against him. Even more surprising, however, was the response of Ayatollah ??jj Shaykh ‘Abd al-Kar?m ??’ir? (d. 1937), a particularly influential marja‘-i taql?d (source of emulation) and founder of “the Institution of Religious Teaching and Guidance” (?awza-yi ?ilmiya) in Qum. While proclaiming his own adherence to the idea of al-raj‘a, ??’ir? indicated that he did not consider it a principle of Islam or even that of Sh?‘? sect. Consequently, its denial did not put one outside of the fold of Sh??ism. What made the exchange both eccentric and a cause for dispute was the central place that the concept of al-raj‘a occupies in Twelver eschatology, dominated as it is by the figure of the Mahd? (or Hidden Imam), his manifestation at the end of time and his soteriological mandate. Al-raj‘a designates, inter alia, his emergence from occultation (ghayba) and his subsequent mission to (re-)establish justice and wisdom throughout the world. It seems, therefore, almost incomprehensible that a Sh?‘? cleric would categorically deny the validity of so fundamental a motif. Even more startling is the failure of a Sh?‘? marja‘-i taql?d to condemn such a denial. Through a close reading of the primary sources, i.e., the writings of Sangalaj?, contemporaneous journal articles, and the rebuttals written by Sangalaj?’s colleagues, this paper proposes the thesis that given Sangalaj?’s unconcealed views, a strong case can be made for the argument that his unconventional theology was intended to provide a foundation for his opposition to the supposed heresies of the B?b? and Bah?’? faiths. The even more anomalous reaction of a person in the position of marja‘-i taql?d suggests that only so compelling a concern could account for his response. As shocking as they were, Sangalag?’s views paved the way for the institutionalization of the Advent of the Hidden Imam in the form of an Islamic government. This study, therefore, can shed light on some of the hitherto understudied grounds out of which the historic developments in Iranian Sh?‘ism in the 1970s emerged.