Certain works of art are made in anticipation of a future response, as a provocation or, on a deeper level, as a kind of vocation, an inspired calling or a summoning to give voice, as in a future meeting of minds. Marcel Duchamp, probably the first modern artist to risk this strategy, characterized the phenomenon as a rendezvous. His first provocation to American artists—to do better than their plumbing and engineering—went unanswered until the 1950s, pending the work of Johns and Rauschenberg. Later, Pollock called on Serra, who responded by throwing molten lead, and on Warhol, who had his party guests answer, urinating on oxidizing pigments. Such rendezvous are mostly conceptual; in our culture of preservation, the meeting is necessarily one of minds, only rarely taking the shape of a physical confrontation or intervention in the original work.1 Yet it was just such a calling that led Seattle-based Shawn Patrick Landis to make a temporary, physical intervention in the most unlikely of artworks—Michael Heizer’s Double Negative (1969). Landis’s rendezvous with this massive earthwork in a remote area of the Nevada desert was direct, physical, and on the same scale, an intervention as a rubbing of shoulders with a giant, slightly abrasive (albeit in the most gentle of ways), like a soft whisper that ultimately, as with all callings that promise protracted reverberations, became critique and homage—spirited and inspired.