TAR FOR MORTAR offers an in-depth exploration of one of literature's greatest tricksters, Jorge Luis Borges. His short story "The Library of Babel" is a signature examplar of this playfulness, though not merely for the inverted world it imagines, where a library thought to contain all possible permutations of all letters and words and books is plumbed by pious librarians looking for divinely pre-fabricated truths. One must grapple as well with the...