A defining characteristic of poetry is its ability to express what might seem to defy words. Hence its indispensability in the medical realm, where clinicians and patients alike so often encounter such ineffable moments as the birth of a child, the end of life, or, as in “Radiance,” the uncertainties of a cancer diagnosis. The poem brilliantly intermingles the wonder of medical technologies that allow us to see inside our bodies with the faith that for many illuminates our inner selves. Juxtaposition works here in several additional ways, with the ironic pairing of the caring son who voices the poem with the danger posed to children by exposure to his temporarily radioactive mother before and after her PET scan; and at the poem’s conclusion, the more complex comparison of the possibly cancer-stricken mother with the radiant Virgin Mary who learns she is bearing God’s son at the Annunciation. The question in the poem’s final lines thus becomes at once an acknowledgment of how faith is tested by illness, and yet how faith itself transcends the suffering, doubt, or fear it occasions. “Radiance” itself, which conjures beauty and holiness despite its medical connotation, is one source of solace. Yet the speaker and his mother in the end seem to take greater comfort in the mystery of “not knowing what she could bear,” with life beginning, conflicts forgiven, and life ending all poetically encapsulated in a healing vision of the sacred.