The Sapphire Circlet - Sherwood & Jarvis, #2

Legendary jewels. Explosive secrets. Queen Victoria's birthday is on the horizon, and everyone on the magical island of Ynis Witrin is caught up in annual festivities. The week-long celebration traditionally culminates with a grand ball, and this year, Princess Beatrice is set to represent the royal family as the guest of honor and wear the famous Iris Circlet, a symbol of the enduring relationship between the British people and the Fair Folk.
There's just one problem: some of the circlet's priceless stones have gone missing on the British embassy's watch. Desperate to avert a crisis of international proportions, the secretary ambassador seeks out the assistance of Dr. Wilfred Jarvis and his brilliant friend Honoria Sherwood. With the ball quickly approaching, Wilf and Honoria must put their wits to the test to track down the stolen jewels.
As they dig deeper into the case, though, they begin uncovering secrets that potentially tie the theft to some of the island's most eminent families - including Honoria's.