—53 Days” ($23.95; Sept. 30, 272 pp.; 1-56792-088-8). Though mystery addicts may balk at its inconclusiveness, readers of every other persuasion will find much to delight them in this deft intellectual thriller left unfinished when Perec, arguably this century’s most accomplished metafictionist and punster (such innovative texts as Life: A User’s Manual,1987, and A Void,1995) died in 1982. The search for missing mystery writer Robert Serval, conducted by this story’s narrator, a teacher “studying” Serval’s uncompleted manuscript The Crypt, rapidly escalates into a voyage to remote (imaginary) territory and a series of droll parodies of literary ancestors (Agatha Christie is a prominent example). Even in its inchoate state (smoothed out by fellow “Oulipo” experimentalists Mathews and Roubaud), Perec’s dazzling gamesmanship offers sophisticated pleasures reminiscent of, and often equal to, the legacies bequeathed to us by his masters Joyce and Nabokov.