It is summer 1890 and the game is afoot. When an elephant escapes from the London Zoological Gardens, Holmes and Watson become embroiled in one of their strangest cases yet. Engaged by a jeweller in fear for his life, the trail leads Sherlock to two secret societies, each pursuing the eight ruby elephants said to unlock a vault containing the lost Nizam diamond.
Standing in his way are some deadly foes: the Archangels: assassins in top hats and tailcoats, hell bent on the murder of the great detective and the acquisition of the treasures of the realm.
The adventure leads the intrepid pair to Lord's Cricket Ground, the Royal Albert Hall, a bizarre series of thefts at the National Gallery, deepest rural Suffolk and ultimately the very heart of the Empire. With high speed chases on Penny Farthings and a cast of eccentric characters, it takes all of Holmes' ingenuity - and a little help from Mycroft - to unravel this elephantine mystery.