Scooby-Doo! Mystery Incorporated Episode 20 The Siren's Song Episode Title:The Siren's Song.Episode Description:Velma is feeling lonely without the gang or any friends. Then she receives a message about "Fish Freaks" in the area around an abandoned oil rig owned by Destroido Corp. Velma decides to investigate by herself. She then discovers that a mermaid called Amy was the one who sent her the message. Amy tells Velma that she knows her and that she needs her help, when the Fish Freaks come out of nowhere and try to grab Velma. She manages to escape and then later asks the gang to help her out. They investigate the oil rig and manage to capture the Fish Freaks. Plus, thanks to Amy, Velma finds out that Angel is not who she says she is.