This essay offers a culturally contextualized reading of Jonson’s Mercury Vindicated from the Alchemists at Court (1615). In doing so, the essay suggests how the masque’s multimodal imagery "works" upon the masquers and spectators. Reading the masque as an embodied hieroglyphic experience consisting of a combination of word, image, sound, and movement, the article argues that Mercury Vindicated parallels the masque’s alchemical subject matter with the "transmutation" of the noble masquers beneath the benevolent light of James’s gaze, and reveals James as an alchemical catalyst whose governance perfects his subjects through politically sanctioned social mobility. Though it seems on the surface to condemn practical alchemists, the masque in fact both performs and valorizes a form of spiritual alchemy. Situating Mercury Vindicated within the intersecting, culturally and historically grounded contexts of early modern alchemical writing and "emblem theory" enables a nuanced understanding of the mechanisms by which collaborative courtly performance was thought to refine its participants individually and collectively. Mercury Vindicated specifically enacts the alchemical elevation of particular courtiers like George Villiers, while the masque in general binds its participants and observers in an ephemeral yet actualized moment of idealized socio-political solidarity.