The Invisible Spy, a four-volume work published in 1754 after three-and-a-half decades of writing for the public, is Haywood's last major work and a fascinating reprise of themes that have emerged in this study. Paula Backscheider, who is one of the few critics to have given thought to this ‘almost unknown work’, writes that it is about ‘the power of print – ethical, economic, and political’, and she is right. The Invisible Spy is about many other things as well, but crucially it is a meditation on authorship in the time of politics, publicity and the emerging public sphere and, perhaps because it engages so thoughtfully what might be called the ‘media issues’ of her moment, it brings us into contact with a Haywood who seems almost postmodern. Just when one seems to be getting a grasp on this most slippery of writers, she gives us ‘Explorabilis’, the ‘author’ of The Invisible Spy, a multiple, fluid and elusive figure who is at once male and gender-indeterminate, self-revealing and self-concealing. The invisible observer seems a figure for Haywood herself, not least in the way he/she deliberately teases the reader with what can and cannot be known about an author at a time when print enabled the construction of a ‘hundred different identities’: ‘Some will doubtless take me for a philosopher, – others for a fool; – with some I shall pass for a man of pleasure; – with others for a stoic; – some will look upon me as a courtier; – others as a patriot; – but whether I am any one of these, or whether I am even a man or a woman, they will find it, after all their conjectures, as difficult to discover as the longitude.’