1889: Mrs Hudson, long-suffering landlady of 221b Baker Street, falls ill and collapses in her home, and is whisked off by Dr Watson to St Bartholomew's Hospital. Perhaps she has developed an overactive imagination thanks to her eccentric lodgers, but it seems she is surrounded by patients who all have skeletons in their closets - on a ward with an unusually high mortality rate. And was the quiet murder she believed she witnessed on her first night simply a hallucination through a haze of morphine, or something more sinister? Meanwhile, Dr Watson's wife Mary has another case in hand. Young boys have been disappearing unnoticed from London's streets for years, and the Baker Street Irregulars whisper morbid rumours of their fates...