Long before Greta (Lauren Cohan) accepts her job as a nanny to that creepy doll, we learn that Brahms was, indeed, a real boy. He was a strange, quiet child who kept to himself. He would often play with the neighbor girl who was roughly his age.
One day, Brahms and his neighbor ventured into the woods, and while Brahms returned home safe, the young girl was never seen again. The rumors around town suggested Brahms had something to do with her disappearance.
On his eighth birthday, Brahms died in a tragic house fire. To cope with their loss, his parents replaced him with a porcelain doll and have cared for him as though he's real ever since.