Older Irish Catholics remember a metaphysical space or place called Limbo. This was the destination of unbaptized infants. They could never enter Heaven because the stain of original sin had not been removed. In addition, they were denied burial in consecrated ground. Fear of such eventualities drove parents to baptize as soon as possible. Nor was this a purely Irish phenomenon. In emergency cases, even baptism in utero was permitted in some parts of Catholic Europe. The centerpiece of this study is the testimonies of Irish mothers and their remembrances of the perils of Limbo, the disposal of infant corpses (in cillíní), and “churching.” Why belief in Limbo has become almost extinct in recent decades is explored, drawing on both demand and supply side explanations. More generally, considerations of Limbo, the unbaptized, and the afterlife give rise to challenging questions as to secularization and even the definition of childhood.