In the year 2042, Sierra, a young graduate student in Classics is shown a new dialog of Socrates, recently discovered, in which a time traveler tries to argue that Socrates might escape death by travel to the future! Thomas, the elderly scholar who has shown her the document, disappears, and Sierra immediately begins to track down the provenance of the manuscript with the help of her classical scholar boyfriend, Max.

The trail leads her to time machines in a gentlemen's club in London and in New York, and into the past--and to a time traveler from her future, posing as Heron of Alexandria in 150 AD. Complications, mysteries, travels, and time loops proliferate as Sierra tries to discern who is planning to save the greatest philosopher in human history. Fascinating historical characters from Alcibiades to William Henry Appleton, the great nineteenth-century American publisher, to Hypatia and Socrates himself appear.