Too Much Radio 4

I often have the radio on when I'm working at home. Of late, I've heard a few (though frustratingly not all) of Anthony Horowitz's "The House of Silk" - a Sherlock Holmes tale of shady London streets and Dark and Mysterious Goings On.

My imagination is always really gripped by these things; and this evening as I walked to my friends' house along shadowy terraced streets I felt a shiver run down my spine...