The year is 1888. London is preparing to celebrate Christmas. Laura Holmes, niece of the popular detective Sherlock Holmes, is offered a very important case: with her inseparable friend Philip H. Hudson, she must solve the mystery of the the disappearance of the famous Maharaja's Diamond, a priceless jewel stolen by some unknown person who left behind him only an enigmatic note. An adventure packed with enigmas and humour set in the streets of Victorian London!