The Rook (The Checquy Files #1)
by Daniel O’Malley (2012)

“The body you are wearing used to be mine.” So begins the letter Myfanwy Thomas is holding when she awakes in a London park surrounded by bodies all wearing latex gloves. With no recollection of who she is, Myfanwy must follow the instructions her former self left behind to discover her identity and track down the agents who want to destroy her.

She soon learns that she is a Rook, a high-ranking member of a secret organization called the Chequy that battles the many supernatural forces at work in Britain. She also discovers that she possesses a rare, potentially deadly supernatural ability of her own.

In her quest to uncover which member of the Chequy betrayed her and why, Myfanwy encounters a person with four bodies, an aristocratic woman who can enter her dreams, a secret training facility where children are transformed into deadly fighters, and a conspiracy more vast than she ever could have imagined.

This is a good read and entertaining throughout, mainly due to the writing prose style that has a very modern feel. A major part of the narrative is the flashback/info-dumps provided be the main character. They provide the world-building and explanation for the characters.
Frequently being extensive and long they often feel like short stories dropped into the main narrative. The disadvantage is that they act to break and interrupt the flow of the main story.

There is a distinct tone shift in the second half as more humour in introduced into the characters and situations. It almost feels like the author is trying to correct for the rather grim-dark tone of the first half. So over all, an engaging read. It looks like the next book will dispense with flashbacks and could be better for it.