It may surprise some to learn that the first science fiction play in the world was written in London in 1687 by Aphra Behn, the first professional female playwright. Almost a century and a half before Mary Shelley wrote Frankenstein, Behn, inspired by Galileo’s invention of the telescope, crafted The Emperor of the Moon as a Restoration farce about the dangers of scientific obsession. Although appearing a century before the Gothic properly began, Behn’s play contains forerunners of the genre, albeit in a farce, reducing their threat to comedic menace. Although not the first to posit the idea that there is a complex civilisation with its own culture on the lunar surface, Behn is the first to use the idea to “gaslight” a citizen scientist. In a typical commedia plot, the wards of a telescope-obsessed businessman, Dr. Baliardo, conspire with their paramours to convince him they are aliens from the moon, the eponymous “Emperor of the Moon.” What is fascinating, however, is the play’s dramatisation of the idea that there is a complex civilisation with its own culture on the lunar surface, the first ever presentation on stage of a lunar (or indeed any alien) civilisation. In carrying out their ruse, the young lovers plan an elaborate ancient history of the moon to be shared with Baliardo by the Emperor. They craft convincing costumes and props, and use the lunar story to gaslight Baliardo into agreeing to the marriages. In an inverse of the Gothic, it is not the ruins we know but the newly found ancient structures on the moon that hold mystery and horror, eventually revealed to be an intrigue to ensure the family lines continue. The plot elements of the Gothic are all present, but pressed into the service of a comedic farce. In this chapter I propose to analyse Aphra Behn’s The Emperor of the Moon as one of the earliest examples of the Lunar Gothic, and a forerunner to later Gothic narratives.