A respected organisation, a hidden purpose, a world-ending threat. The protagonist is 12-year-old Margaret Elizabeth Thatcher. And no, having the same name as a somewhat infamous former Prime Minister is not something Maggie is especially fond of, especially when adults can judge her harshly simply because of her name. Maggie is also not thrilled about her severe food allergies, asthma, and anxiety. Despite this, she attends a fun ‘apocalypse training’ camp at Dux Manor in London, a camp run by the Wayfinder Girls (a pseudo Girl Scouts / Girl Guiding organisation). Attending any camp is not a simple matter for a food allergic family. Maggie’s mum brings all of Maggie’s food in a specially labelled chilly bin and negotiates with the camp staff for a place for Maggie to prepare her food, even though it had all been pre-arranged. They are shown to a separate kitchen by Lady Marie Studfall, one of the highest ranking leaders in the Wayfinder Girls. Maggie’s mum leaves Maggie in the care of Lady Marie, and Maggie’s best friend Anahira Waititi. Anahira claims Taika Waititi is her uncle, and Maggie can never work out if she’s telling the truth or not, because Anahira always says it with a huge grin on her face. During camp Maggie and Anahira discover a secret programme the Wayfinder Girls keep hidden from the world, a programme called Guardians. The Guardians are a specialist Wayfinder Unit defending the world against inter-dimensional threats. Anahira and, somewhat surprisingly, Maggie are invited to join this specialist unit. Anahira wants to join but Maggie is not so sure, she is having difficulty enough coping with this world as it is, let alone having to deal with any others. With Anahira’s encouragement and Lady Marie’s insistence that it is perfectly safe, Maggie joins Anahira and they both start their training as Guardians. But something goes terribly wrong during Guardians training at the Chiltern Hills campsite. Maggie finds herself tricked into serving Tylwyth and Teg, two Fey (Faerie folk) who somehow believe Maggie to be the Iron Lady, whatever that is. Tylwyth and Teg are not your typical Fey, for starters they wear football shirts, and they love ice-cream and movies. They are certainly mischievous and Maggie doesn’t know if she can trust them. Maggie is tasked by Tylwyth and Teg to retrieve the Mynydd o Olau, a magical artifact lost from the world of Faerie that the Fey need back. Maggie discovers that the Mynydd o Olau is none other than the Koh-i-Noor diamond sitting on the front of the Queen Mother’s Crown held securely in the Jewel House in the Tower of London. It is simply impossible to get that for Tylwyth and Teg. But if she doesn’t return the diamond to the Fey, the world will encounter no end of scary magical threats and Maggie herself will be taken to the Faerie world, never to return. Maggie also learns that she only has three days to get the job done, for the diamond must be returned by All Hallows Eve. Will Maggie be able to conquer her fears and do the impossible?