Madame Vastra, the fabled Lizard Woman of Paternoster Row, knew death in many shapes and forms. But perhaps one of the most bizarre of these was death by snow…On a cold day in December, two young boys, tired of sweeping snow from the workhouse yard, decide to build a snowman and are confronted with a strange and grisly mystery. In horrified fascination, they watch as their snowman begins to bleed…The search for answers to this impossible event will plunge Harry into the most hazardous and exhilarating adventure of his life. He will encounter a hideous troll. He will dine with a mysterious parlour maid. And he will help the Great Detective, Madame Vastra, save the world from the terrifying Devil in the Smoke.