In the summer of 1968, Lissy Vaughn comes to Oxford to run a simple, scholarly errand.

After a year at Blackhurst College, she has found her place among the young men and women training to investigate the occult. Now, with Bridget and Mick at her side, Lissy is sent to a city of ancient colleges where secret libraries are hidden behind walls of honey-coloured stone. A city where every cobble has a thousand years of history.

The task should be simple. An old professor’s will leaves his collection of rare books to the Bodleian, and all Lissy has to do is help examine them for any possible signs of magic. A boring and thankless job for three students, just before they leave for the summer holidays.

But someone else wants those books.

When a thief strikes with brutal force, what began as an errand becomes a chase through Oxford’s streets, through a city that does not easily give up its secrets.

Traces of alchemy lead to unnatural black roses, growing under the light of an impossible sun that only shines through shards of cursed glass. All the work of a man willing to kill for forbidden lore that should have been buried with its owner.

To stop him, Lissy must unlock the ancient mysteries of Oxford, and the terrifying truths of this city of gold. Her friends are bleeding. A madman is hellbent on completing his great work.

Before the sun rises again, Lissy must decide what she is willing to pay to learn what truly lies on the far side of the dark glass, beneath an infinite, golden sun.