'The list of literary couples is a distinguished one: Percy and Mary Shelley, Virginia and Leonard Woolf, Scott and Zelda Fitzgerald, Simone de Beauvoir and Jean-Paul Sartre, to name a few. Curiously, none of the just-mentioned duos ever wrote and published a book together. Whether due to differing prose styles or competing egos — or both — cohabiting and co-writing is highly uncommon.' (Introduction)