When Dennis comes into possession of a book that shouldn't exist, a new chapter in his life begins and a different, alternate London reveals itself - and with it a cast of characters each more unlikely and fantastical than the last. Long London occupies precisely the same geographical space as our London ­- but it is a city built from dreamscapes and art, from fiction and nightmares.

This is the London of penny dreadfuls and William Blake's dark woodcuts, colliding with Dennis' own time - that of a post-war capital, not long rebuilding itself from its own recent nightmare of war and bombing.

This series will be a mad and magical A to Z of the greatest city on earth - with a tale of friendship, murder, betrayal and mischief and the very centre of the map...