During Mia's birthday, when everybody sings 'Happy Birthday To You', Susanna (Carice van Houten) yells "Hieperdepiep! Hurray", which means "hip hip" in her native language, Dutch.
The director said that editing the film was a big challenge. It was a long, complex process because of the story's dual structure.
If Clive Owen's character's name is John Farrow and the daughter's name is Mia, then she's Mia Farrow.
'Daniel Bruhl' was very keen to work with Juan Carlos Fresnadillo after having seen his work on Intacto (2001) and 28 Weeks Later (2007). Clive Owen, on the other hand, hadn't seen either but quickly rectified that when he signed on.
John Farrow was a movie director in the 40s and 50s. Mia Farrow is his daughter. Clive Owen plays a character named John Farrow with Mia as his daughter.