The speaker and a companion descend into a landscape where water comes out of the earth, and the poem treats the trip almost like a pilgrimage. Everything is physical and close up: flowers growing from the ground, roots pushing into cracks in the rock, and a loud rush of water that drowns out any other sound. Even the "limestoned voices" seem to belong to the stone itself, too muffled to hear over the "gasp & suck" of the water.
The mood moves from wonder to something more uneasy and then to awe. The water is beautiful but also a little rough, with scum and debris caught in its throat. When the speakers crouch in the sun and pray "for a rain of calcium," they seem to be asking to become part of the slow process that builds the rock. The ending lifts the eyes upward. A sky that is "impossibly high & thin" makes the climb down feel like a passage into a different sense of scale, small and humbled.