Numerical problem solving in search of the unknown quantity: that structure has served more than once as a stand-in for relations of breath, skin, and flesh, most notably when—in a shifting engagement with the objects of representation—the accuracy of description unites with the pleasures of sound. One way to stimulate a critical standpoint specific to questions of culture and medium, and to markers of sex and social identities, is to rehearse the histories of self and other as per the “custodies” of desire, as coupled to the contingency of method in the time lags of the past in the present.