故事改编自Araminta Hall的2021年小说，聚焦Nancy Hennessy的死，外人看来她的生活是完美的，漂亮、富有、深得相识的人的尊敬和喜爱。而她被谋杀后，留下两个最好的朋友、深爱她的丈夫和女儿，以及一个她至死都未说出身份的秘密恋…

During a visit to friends, Sara begins having visions and is attacked by an unearthly creature in her friend's swimming pool; she soon discovers that anyone who comes into contact with the water is in danger and she is d…