Some manuscripts of the book of Acts have a slightly longer version of the book that is familiar to us, a version called the Western Text, which is made up of small amounts of additional material scattered throughout the work. Various theories have been proposed to account for the existence of the Western Text, although no real consensus has emerged. In recent years this material, long thought to be inauthentic, has been reexamined by a number of scholars who have come to the conclusion that it may derive from Luke, the author of Acts. This study puts forward the ingenious thesis that Luke left Acts unfinished at his death, and that the work of his posthumous editors has led to the existence of the two versions of Acts that appear in our manuscripts.