A spy in the house by Y. S. Lee

Walker, 2009. ISBN 9781406315165.
(Age 12+) Recommended. Mystery. After Mary Quinn lost her parents, her life deteriorates and she is forced to steal to stay alive in the grim Victorian age when orphan children scavenge on the streets. Sentenced to death for theft at the age of 12, she is rescued from the gallows and taken to Miss Scrimshaw's Academy for Girls, where she turns her life around. After five years at the Academy, she is ready to take on a new life and is offered a place in the Agency, which investigates cases involving criminal acts and when sufficient evidence is collected, the criminals are turned over to the police.
Mary is sent off to live with the Thorold family, as a companion to Angelica, a bored, spoilt girl, who is also a gifted musician. Mr Thorold is suspected of fraud and Mary is to keep her eyes and ears open and help find evidence to convict him. When Mary meets James, a young man who also wants to find out about the Thorold family, all sorts of exciting adventures follow. This mystery was gripping with lots of red herrings scattered throughout the book and enough twists and turns to keep the reader guessing what was going to happen next. There is also an intriguing mystery about Mary Quinn's father, which I hope will be explored in the sequels, The Body at the Tower and The traitor and the tunnel, which I am looking forward to reading.
Right from the first pages I became really involved in the feisty character of Mary Quinn. Lee has created a wonderful heroine whose adventures kept me enthralled to the end of the book. I loved how independent she was and how the Agency was prepared to take girls who were intelligent and had potential and turned their lives around. The witty repartee between James and Mary also brought a dash of humour to the book.
A fast paced, well written book, this would be a good introduction to the mystery genre for young readers.
Pat Pledger