The movie isn’t scheduled to begin production until the summer, but it looks like this coming of age film has gained another actress in this allegory filled adaptation of the book of the same name.

Deadline is reporting that Kelly Reilly has signed on to play a school nurse with a very dark side in the movie ‘Innocence.’ Reilly is best known as Mary Watson in the Robert Downey Jr. ‘Sherlock Holmes’ films and also played the role of Muriel Brassler in ‘Me and Orson Wells’ starring Zac Efron and Gareth Hagon. She is well known in the UK starring in the ‘Above Suspicion’ series.

‘Innocence’ is based on the 2000 young adult book by Jane Mendelsohn and is about a moody teenager named Beckett who just lost her mother and moves to the Upper East side of Manhattan with her father. She soon discovers her new elite private school is infested by vampires. Here is the official synopsis:

In this modern Gothic vampire story, a recently bereaved teenage girl finds herself the focus of everyone’s attention at her elitist private school where life is steeped in tradition and ceremony. As she deals with her mother’s death, her father’s new relationship, and falling in love for the first time, she is blissfully unaware that the school is home to a house of vampires who have their sights firmly set on capturing her and making her the subject of a ritual virgin sacrifice.

As she struggles against time to uncover the truth, the vampires carefully close their net with those around her questioning whether or not she is losing her mind.

Reilly will be playing the role that was originally supposed to have gone to Julianne Moore. No comment was given as to why Moore is no longer part of the cast (maybe she decided to play Carrie’s mom instead?). The role of the school nurse is a pretty significant one as in the book, she begins to date Beckett’s father and eventually becomes her step-mother.

Reilly will be joining Abigail Breslin (‘Ender’s Game’, ‘Zombieland’) and Chloë Sevigny (‘Big Love’, ‘American Psycho’) who signed on for the movie last year. After finishing her role in ‘Ender’s Game,’ Breslin will head over to ‘Innocence’ to play the lead role of Beckett.

The screenplay for ‘Innocence’ was written by Tristine Skyler and has been described as a gothic ‘Rosemary’s Baby’ type of film. Hilary Brougher will helm the project that is being produced by Christine Vachon and Pamela Koffler of Killer Films in conjunction with Bankside Films.