As Mexico City celebrates Dia de lols Muertos – The Day of the Dead- Carmen tracks a young art thief who's just been recruited by V.I.L.E.
On a corn farm, Spin Kick and Fly Trap are tracking Carmen Sandiego. They follow a signal to a clearing and try to attack. It turns out it is a scarecrow with Carmen's clothes on them. Nearby, Shadowsan smiles, having set the trap, and drives off, satisfied that his goal was accomplished.
In Mexico City, the people are celebrating Day of the Dead. Meanwhile, Carmen is at a museum after realizing that a ton of art has been stolen and this one was yet to be robbed. It included a particular piece by Freda Khalo. Carmen notices that one youthful person who is take notes of exits and entrances, as well as hallway. After they leave, they wait until celebrations for the Day of the Dead parade occur later on.
The girl thief Sonia re enter the museum, proceeds to take the painting Self-Portrait with Monkey. Carmen tries to stop her but she escapes through a window. She brings the portrait to her handler Marta, but it was actually a poster; Carmen had already switched the real one to a fake one.
Marta tells Sonia about a school for her and Sonia seemingly rejects it, deciding to walk outside. Carmen takes the opportunity to confront Sonia, and tells her not to go down the same path, but is rebuffed as Sonia is seemingly interested in that.
On VILE island, the faculty are having their own Halloween event to themselves. Professor Maelstrom is in a clown costume inspired from IT, Countess Cleo as Cleopatra, Dr. Bellum as an astronaut, Coach Brunt as a cowboy. They try a bob with haggis, but Brunt is revolted and answers the door, who happen to be cleaners trick or treating.
Carmen confronts Marta, who immediately recognizes her. She points to a Pre-Columbian artifact, says she cares too much, and throws it at her; it was not an artifact but an electro-static shocker device that incapacitates her. Marta gets back the book stolen and puts it in a jar. Then she drives an unconscious Carmen in a car and ties her on a plane.
Player tells Ivy and Zack he lost contact and they head to the last known location. There they find the book, and Zack throws up in the same jar. Marta returns, tries but fails to use the same trick that got Carmen.
Zack and Ivy head to the airport and see the plane ready to leave. Sonia had gotten on it and there are Spinkick and Fly Trap.
The plane takes off but is ordered to back land. In the back of the plane, Sonia secretly tells Carmen that she had a change of heart and she was playing along with the people, saying that she thought the school of thieves was a set of losers. Freeing Carmen, thy fight Spinkick and Fly Trap until the plane lands, and they escape by driving back to the place where they had been before.
In the end, Team Red honors the dad of Carmen, knowing that he is gone. They discover the book with VILE information is gone, having been stolen by Sonia.