When Carmen is tricked at a heist in China, she decides to get even with a Halloween surprise. She decides to set up a haunted house with items she's recently stolen. Zack is a bit frightened by all the spooky stuff in the house, and has to convince himself it's all fake.

Maelstrom, a thief who was caught by Carmen during her time as ACME-detective, escapes from prison, swearing revenge on her. At first, it is reported to the detectives that he died during his escape. The detectives are curious about him and The Chief tells them about his adventure with detective Carmen. During that adventure, Carmen and a robot version of the Chief stop Maelstrom from stealing the wreck of the Titanic. At the conclusion of the story, Ivy and Zack find out that Maelstrom is alive and see the opportunity to catch both Carmen and Maelstrom. However, when the detectives sneak aboard Maelstrom's ship, he captures them.

Zack and Ivy escape Maelstrom's ship and find out that Carmen still believes that Maelstrom died in his try to escape from the prison. Carmen wants to give him a worthy Viking-like funeral in Norway. Zack and Ivy find her beginning to give him such a funeral and are about to tell her that Maelstrom is alive when Maelstrom appears in a ship beside Carmen. He challenges her to come after him or die, and then speeds off. Carmen manages to get Zack and Ivy aboard her ship and they make an agreement to join forces to capture Maelstrom. Carmen remembered a clue he left, so she and the detectives follow it to Williamsburg Virginia where Maelstrom captures them and publicly humilates them in the stocks of the town square. Zack and Ivy escape and help Carmen do so as well. They get separated and the local police arrest the detectives for freeing Carmen!

The Chief manages to convince the local sheriff to free Zack and Ivy. They meet up with Carmen again and persue Maelstrom. Malestrom begins to steal items and frames Carmen for their thefts! He wants to ruin her reputation as thief with a conscience.

Carmen's henchman Mason Dixon steals her time machine. Suddenly, he is the leader of V.I.L.E. and Carmen is only his henchwoman. Zack and and Ivy have to restore Mason's damage, and also stop him from trying to change the outcome of the Civil War

All ACME detectives are making holidays on the Seychelles. Josha, the genius of the detectives, is in love with Ivy but she doesn't notice. When Carmen tries to steal Josha's latest invention, she tries to distract the detectives by stealing highly romantic items.

When Carmen tries to steal some treasures from industrialist Malcolm Avalon she discovers a painting representing her mother. At the same time Lee Jordan takes the decision to become the new leader of V.I.L.E. Avalon tells Carmen, that the medaillon she has with her, representing the same woman as on the painting, was a gift for his daughter, but he says, that Carmen can't be his daughter because she died in a fire and she would never have become a thief. To convince him she turns herself in to the police. When Lee abducts Avalon, she breaks out again. Lee says, that she will only see her father again if she works for him...

This was the last episode made, leaving us with the question of if Carmen really found her father, and will she stop her life of crime.