Jack Mason grew up as an acrobat in a circus. Now, after the tragic death of his parents, he must live inside the gloomy walls of Sunnyside Orphanage in London, a city of fog and snow, filled with airships, steam cars and metrotowers that stretch into space. Luckily for Jack, he's taken under the wing of the brilliant and eccentric detective Ignatius Doyle. Little does he know how dangerous life is about to become!