This is an excellent psychological thriller, living in Manhattan young couple Brad (Sam Rockwell) and Abby (Vera Farmiga) ushered in their second child, the birth of the baby gives the couple great joy, all the family's attention revolves around her. However, with the passage of time, happy families began to have many strange accidents, and there were cracks in the relationship between husband and wife. The newborn baby girl was originally quiet and lovely, but she cried in the middle of the night for no reason. Abby's hallucinations made her nervous breakdown and the whole family was shrouded in a mysterious force. Finally, Brad noticed that the suspicious conditions had something to do with their 9-year-old son Joshua (Jacob Kogan), who was praised by his teacher for being extraordinarily smart at school. he has a higher IQ than his peers and an adult mind, but on the surface, he loves and cares about his newborn sister as much as his family. Are these accidents done by someone in the dark or by accident? what does Joshua's calm appearance mean?