Professor Alfeus Allpatch is the foremost theorist at the Observatory of the Unseen — a tall, slightly threadbare scholar in a coat of mismatched squares, each square a quote from a treatise he could no longer find. He studies the physical mechanics of Void propagation: how forgetting moves through fabric, how a story's mass affects its decay, why some places fray faster than others. His paper, Observing the Unseen, is required reading among the Threadbare Theorists. Alfeus is patient with apprentices, ruthless with his own assumptions, and never quite warm enough — a problem his colleagues attribute, fondly, to too much time staring at the absence of things.