The ending comes back to the idea that the pool has healing powers but it must take a sacrifice in return. Rebecca—the girl from the opening scene who drowns and kicks off this mundane attempt at horror—is the “sacrifice” for her sick brother. (We do find this out as Eve investigates and talks with Rebecca’s mother, who knew what was happening.) This spiritual spring water that the pool is built above targets Ray because he comes in contact with the pool first, which we see at the beginning when he falls in trying to pick up a baseball. At this point, the governing haunted entity of the pool decides Ray deserves to be healed. Ray’s son Elliot becomes the target for sacrifice because he is most likely seen as the weaker link in the family. It sucks to say, but it’s likely true. Dad was an all-star baseball player, mom is a teacher, and his sister, Izzy, is a great swimmer. Throughout the film, Elliot tries to play baseball but it’s evident he most likely won’t make it past Little League. Coming into the end of the film, here’s where we stand: we have a haunted pool which heals people in exchange for a sacrifice; Ray’s MS is getting better, sparking his desire to return to the professional field; the pool has chosen Ray’s son, Elliot, as the sacrifice because, as we can guess, Elliot is the weak link; and Eve becomes a paranormal investigator to save her family. Let’s get into it. The entity takes over Ray who starts to turn on his family. Eve jumps in the pool to save her son, who has now been taken underwater by the entity as the sacrifice. Outside the pool, Izzy attempts to stop Ray who is determined to be healed (since he is possessed and not thinking straight). She hits him with a baseball bat which apparently is the way to expel a demon from your dad’s body because Ray returns to his normal self. With Elliot under the pool’s curse and near death, Ray—who is now real Ray and not possessed Ray—knows his son will die unless he gives back his desire to be healed. But the pool needs a sacrifice to stop this madness. With his family watching, Ray walks into the pool and sacrifices himself to save his family. The family fills in the pool so no other family can be tormented, and remains in the house so they can still be close to their dad.