'I was in the wrong London. It was horrible. I'd fallen in by accident, and it was all alive and trying to eat me.'

The year 1949, the city London.

Hapless second-hand bookseller Dennis stumbles through a city still shaking off the war. While out procuring inventory, Dennis's life changes forever when he chances upon a novel that shouldn't exist; an entirely fictional book from inside another novel.
The book hails from The Great When, a magical shadow-London, where reality blurs with fiction and concepts like Crime, Poetry and Riot are incarnated as mystical beings that stalk the streets. This discovery brings terrible danger, as the book's presence leaves the doorway open between the two Londons, and The Great When must remain a secret.
Soon Dennis finds himself in the city's occult underbelly, negotiating sorcerers, gangsters, and murderers some imaginary, some all too real, and all with plans of their own. If Dennis cannot return the book and close the gate, he risks dire repercussions...
Neither London will ever be the same again.
History collides with magic in The Great When. Dark, ridiculous, propulsive, Sunday Times bestseller Alan Moore opens the gates to capital metafictional chaos in the genre-busting first instalment of the Long London series.

'It does what fantasy does best which is show us something beyond our experience - this shows us something absolutely new' Susanna Clarke
'A breathless time-travelling classic. Savage, humane, comic, terrifying' Iain Sinclair

'Brilliant and so powerfully imaginative' Adam Curtis

'A weird book and a complete joy' Mariana Enraquez
'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