Thanks to NetGalley and Simon and Schuster Books for Young Readers for the opportunity to read and review The Fourth Ruby by James R. Hannibal! This sequel to The Lost Property Office finds the Buckles siblings, Jack and Sadie, relaxing by the fireplace. The siblings begin another quest with Gwen while they search for a thief together and the item the thief is after, the fourth ruby. The Mongolian history was interesting to read about and I liked how the author tied it into the Buckles’ lives. Jack continues and is determined to help his father throughout this new adventure even though many dangers are lurking. Fun steampunk mystery! 4 stars.