A cracker . . . Utterly convincing

WW2, somewhere in southern England. Our mathematically and psychically gifted soldier-narrator is on a secret mission . . . Despite the diversity of its elements, this is a well-paced, enjoyable read, which effectively combines ideas generally not seen together in WW2 fiction, and certainly not children's fiction

The real-life location, historical detail and plausible contemporary voices give this conviction

Highly visual and exciting . . . dystopian vision that is expertly crafted

Fights, flights and regular plot twists

A compelling, compulsive, atmospheric story . . . The movie is already rolling in my head

Zips along at break-neck pace, each short, action-packed scene feeding into the next, ideal for teen readers with Playstation attention spans . . . McGann's direct, gritty style of writing certainly packs a punch

I envy any young reader discovering this enchanting new series and writer. It's such a clever idea to marry the Malory Towers girls' boarding school novel with the Golden Age of detective fiction, and doing it through the eyes of Hong Kong Chinese heroine Hazel Wong is an especially good touch . . . A real treat

Angela Brazil meets Agatha Christie all mixed up with some Sherlockian tips and winks that made me snuggle down and read with a contented smile. It is a jacket potato on a winter's day book; warm, satisfying, filling . . . This is such a glorious book and it is one which has reinterpreted the school story for the contemporary reader and opened it up with a swift moving and accessible plot line. In Star Trek terms, it is the next generation as compared to the original series. It is very, very gorgeous. Daisy is glorious. Hazel is awesome. I want more, please. It's as simple as that

Irresistible . . . It feels both delightfully old-fashioned and current - a difficult balance to pull off, but it's been done with style here. Imagine Agatha Christie visiting Malory Towers and add in some modern sensibilities and you are about there. The plot twists and turns like nobody's business and I didn't guess the real culprit for a very long time, but the real draw is the relationship between the two main characters. Daisy and Hazel are like chalk and cheese but they are perfect foils for one another and together, they make a brilliant detective duo

I absolutely loved it - it's charming and witty and there's so much in terms of in-jokes and she really grabs hold of all the traditions of this type of story and runs with them. You've got bunbreak, squashed fly biscuits and dormitories . . . but at the same time as this thrilling murder mystery

A gentle, entertaining story.

A Bank Street College of Education Best Book of the Year—and it's an "Outstanding Merit" title!