Sen Sen is a boy in Taiwan mourning his older brother's death. When he discovers a streaming website that his brother followed it leads him to an old lady with terminal cancer. Together they form an unlikely bond.

When a spirit medium is called to exorcise a demon from a possessed man, he is unknowingly captured in the act by two students looking to document the process. When the students accidentally release the devil fish demon into the world, it is up to them and the spirit medium to send it back to the hellish world from where it came.