Grace's family are wardens of the incredible Griffin Map, using its teleport technology to fight crime across Moreland. Right now it's all systems go at Griffin HQ, where Grace, her mum and her brother have their hands full answering a huge number of calls for help. They could really do with another warden on the team - but Mum believes their important work should be kept inside the family.

Meanwhile, Grace is investigating a series of puzzling petty thefts. The clues lead her to a ramshackle castle on a lonely island, where the mystery only deepens. Will Grace be able to track down the thief?Award-winner Vashti Hardy celebrates kindness, found family and brilliantly inventive kids in this mystery-led, steampunk companion to The Griffin Gate.