One of our greatest living storytellers takes a tour through the dark and beguiling streets of a magical London: history and myth collide in this story of magic and murder by Sunday Times bestselling master of modern fantasy Alan Moore.

The year is 1949, the city London. Dennis Knuckleyard is a hapless eighteen-year-old who works and lives above a second-hand bookshop. One day, on an errand to retrieve rare books, Dennis discovers a book that simply does not exist. It is a fictitious book, yet it is physically there in his hands nonetheless. How?

Dennis has stumbled on a book from the Great When, a dark and magical version of London that is beyond time. There, epochs blend and reality blurs with unreality, while concepts such as Crime and Poetry are incarnated as wondrous and terrible beings. If Dennis does not take this book back to the other London, he will be no more.

So begins a journey delving deep into the city's occult underbelly and tarrying with an eccentric cast of sorcerers, gangsters, and murderers - some legendary, some all too real, and all with their own intentions. Soon Dennis finds himself at the centre of an explosive series of events that may alter and endanger both Londons forever...

Magnificently written, propulsive and darkly sparkling with humour, The Great When is Moore's most imaginative work yet, and the first in the fantastic new Long London series.

'Brilliant and so powerfully imaginative' Adam Curtis

'A masterful step from one of our very best, uncompromising storytellers; Moore peels back the layers of London and reveals not only the history we know, but the histories that could have been, and, underneath it all, both the dark and beautiful truths about who we are as a nation.' Heather Parry