"Every reading is, strictly speaking, unrepeatable; something in it, of it, will vary. Recollections of reading accumulate in relation to this iterable specificity; each takes its predecessors as its foundation, each inflects them with its backward-looking futurity." In Ex-foliations, Terry Harpold investigates paradoxes of reading's backward glances in the theory and literature of the digital field. In original analyses of Vannevar Bush's Memex and Ted Nelson's Xanadu, and in innovative readings of early hypertext fictions by Michael Joyce and Shelley Jackson, Harpold asserts that we should