Successful photogorapher Janis (Penelope Cruz) meets a forensic archaeologist, Arturo (Israel Elejalde) and gets him interested in investigating a war crime grave (from the civil war) in her home village. 9 months later she is pregnant and giving birth in hspital sharing a room with a young mother-to-be, Ana (Milena Smit). Both are single mothers. Both babies are taken away for observation overnight and then they return to their homes.

Arturo and Janis have separated (he was married and she wanted the baby on her own). He visits to see the baby and says he doesn't think it is his. This plants a seed of doubt for Janis and she takes a maternety test which confirms she is not the mother.

She bumps in to Ana and learns her story - she was a gabg rape victim at school, but now her baby has suffered cot-death and she has left her mother and is working in a cafe nearby. Janis is looking for a new babysitter and invites Janis in. She covertly does a maternity test on Ana and her own baby and learns that the babies must have been swapped.

Eventually she tells Ana the truth and Ana leaves, with the baby. Arturo reappears with news that he has got the grant to investigate the war grave in Janis village. The two stories intersect as the truth of the grave is revealed for the villagers like the truth of the birth swap. Janis and Arturo are together again and she is pregnant and Ana is a close friend with her own real baby.