Evaline Stoker and Mina Holmes have reluctantly agreed to act as social chaperones and undercover bodyguards for Princess Lurelia of Betrovia, who has arrived in London to deliver a letter with the location of an ancient chess queen that’s been missing for centuries. But when the letter-which will heal a centuries- old rift between England and the Betrovians-is stolen out from under Evaline and Mina’s watchful eyes, the two girls are forced into a high stakes race to ensure they find the chess queen before anyone else does … including their foe, the Ankh. For the chess queen is not only a historic symbol of a woman’s political power, but it has literal power as well-the queen will unlock the chessboard, revealing both jewels and ancient secrets the Ankh would kill to possess. It will take Mina’s smarts and Evaline’s strength to beat the thief and untangle this mystery before it is too late.