After her successful prosecution of a powerful gangster in the south of France, examining magistrate Cecile Galant has been transferred to Versailles for her own protection. The workload is heavy: an aristocrat accused of shoplifting, a girl who has gone missing and then a bizarre case in the grounds of Versailles. An Oxford student, Marina Cassatt, claimed to have witnessed a murder but by the time she has contacted the police and returned to the scene, no trace of the crime can be found. Could Marina's vision be linked to the incident in 1901, when the Principal and Vice-Principal of St Hugh's College, Oxford claimed to have travelled into the past when walking by the Petit Trianon? When an attempt is made on Cecile's life, she decides to visit Oxford and explore in more detail exactly what Marina saw in the chateaux gardens.