The biggest, most beautiful diamond in the whole world has been stolen from Buckingham Palace! Nobody knows how the sneaky thief managed to take the Siberian Diamond from right under the Queen’s nose – but Shylo and the brave Royal Rabbits of London will do whatever it takes to solve the case and return the jewel to its rightful place. Then they discover that Russia's elite sharp-toothed secret-agent minks are in London, could they have anything to do with the theft...? But nothing is quite what it seems, and the Royal Rabbits soon realise they might need a bit of help from an old friend to solve this mystery...