At the end of the film, Dr. Mark pushes Prot in a wheelchair and mentions the missing Beth. This ending is unforgettable. Are there any aliens in this movie? Or is it just that Prot was hit and jumped into the river, causing mental problems? In fact, there are some hints in the film: 1. Prot met Dr. Mark for the first time and said, Don't worry, I won't be parasitic on you. 2. In the bluebird incident, Beth said to Potter, I know you are a bluebird. 3. Dr. Mark knew Potter's past and said to him: You are Potter (pay attention to the full name). Potter said: If you find it, take good care of him for me. 4. Beth's composition: I am homeless, which conforms to the characteristics of K Paikes, and my perception and insight into things are different from ordinary people. Refer to the tip above: "Yes" there are aliens in this film, first described by Prot and hypnosis. Parasitic on the bluebird in the hospital again, Beth can feel it. After Dr. Mark learned about Prot's past, he suggested that he should take good care of him in the future, which means that the ending is like that, suggesting that you should take good care of this body (non-death state) after I leave. Finally, he left and took Beth's parasite with him. Porter should have lost consciousness before he was parasitized. Maybe parasitism is the only way to save his friend.