This book presents a detailed critical analysis of a period of significant formal and thematic innovation in Muriel Spark's literary career. Spanning the mid-1950s to the mid-1970s, it identifies formative instances of literary experimentation in texts including The Comforters, The Driver's Seat and The Public Image, with an emphasis on metafiction and the influence of the nouveau roman. As the first critical study to draw extensively on Spark's vast archives of correspondence, manuscripts and research, it provides a unique insight into the social contexts and personal concerns that dictated her fiction.