The London Silver Vaults - for well over a century, the largest collection of silver for sale in the world. Not somewhere you can murder someone and vanish without a trace - only that's what happened. The disappearing act, the reports of a blinding flash of light and memory loss amongst the witnesses all make this a case for Detective Constable Peter Grant and the Special Assessment Unit. There is a world hidden underneath this great city - the new "Rivers of London" novel.