More than a hundred years after its publication, An Adventure remains the most convincing ghost story of the twentieth century. On a clear day in August 1901 two respectable English ladies visited Versailles for the first time, and found themselves without explanation in the gardens of the Petit Trianon in 1789, walking long-lost paths through a forgotten landscape, and meeting and talking to gardeners and courtiers whose speech and address were those of a previous century. And, on the steps of the palace given to her by her husband, King Louis XIV, sat Queen Marie Antoinette, sketching. Published in 1911, the book in which they described their adventure was greeted both with fascinated interest and howls of derision. The details, supported by their own often exhaustive research, made it difficult even for the most antagonistic critics completely to demolish it – apart from the personalities and costumes described, the landscape they detailed – unlike that of 1901, accorded with manuscript 18th century maps. While modern readers most often consider their story the result of a curious mutual delusion of the two women, the body of their narrative is still often irritatingly convincing. No-one interested in the occult, in the possibility of some kind of ‘time travel’, can afford not to read this still fascinating account of ‘am adventure’.