Muu is the generative spirit of the womb in Guna therapeutic cosmology, the power that forms and quickens the unborn child and that dwells at the deepest of the stacked layers running down through the body and the underworld. In normal gestation her work is benign, but when labor is obstructed she is understood to have seized the burba, the vital soul, of the laboring mother, and to have overreached her proper domain. The great curing chant Muu-Igala, 'the Way of Muu,' recorded by Nordenskiold's collaborators and analyzed by Holmer and Wassen and famously by Levi-Strauss, narrates the shaman's journey along the road to Muu's abode, accompanied by carved spirit-helpers, to negotiate the soul's release and restore the child's safe birth. Sources differ on whether Muu names a single grandmother-spirit or a class of uterine powers.