The Royal Society of London plays home to the greatest minds of England. It has revolutionised philosophy and scientific knowledge. Its fellows map out the laws of the natural world and usher in an age of enlightenment. To the fae of the Onyx Court, living in a secret city below London, these scientific developments are less than welcome. It is now 1757 and magic is losing its place in the world. Science threatens to expose the fae's hidden city to hostile eyes. To make matters worse, the calculations of Sir Edmond Halley predict the return of a comet in two years time, the same comet to which the powerful Dragon that caused the Great Fire of 1666 was banished. So begins their race against time. It will take both magic and science to save London, but reconciling the two carries its own danger...