Mademoiselle Moreau, also known as the Le Monde Reporter, is the villain of Mystery Train Island.
Moreau is dressed very fancily. She has blonde hair and it's done up high and topped by a beige hat with pink flowers. She is wearing a skirt and blouse in muted colors. There is a mole on her cheek. She wears a pinkish-red lipstick.
Moreau is a news reporter, and a France fanatic, even decorating her temporary cabin on the train with things from her home country. She is an extreme patriot; she will go to drastic measures to stop or destroy anything that can upstage France or the Paris World's Fair.
Moreau's first interaction is with you on the train. She'll give you an edition of the newspaper she reports for, the Le Monde. (It's not necessary for the plot, but it's interesting to read — that is, if you know French.)
Later when the train goes through the tunnel (as there are lights on), she sneaks into Thomas Edison's cabin and steals his motion capture device. Then she goes into the coal car while the Coal Man is getting a snack, and pulls the stop lever. In the confusion she is able to put the device in her suitcase without anyone spotting her, however, she accidentally gets coal marks on it. By switching name-tags with Nikola Tesla and covering the French items in her suitcase, then sneaking outside and tossing her suitcase key into Telsa's room, Moreau makes it as though Telsa is the thief. She heads back on the train. She walks towards the Luggage Car and notices you examining the coal marks. She tosses scissors at you in an attempt to discourage you from inspecting it further, then slips away.
Later she returns to the Luggage Car, and waits. Soon you arrive and she manipulates you into pretending to be the Porter, so you find the key in Tesla's cabin. You open her suitcase, thinking it belongs to Tesla, and find the missing device. You shout in surprise of this and Moreau informs a Pinkerton Guard, who arrests Tesla. Now that Tesla is eliminated, Moreau continues her true plan. First she sneaks into Erik Weisz's cabin and steals one of his lock-picks, then goes into Tesla's cabin and unlocks his trunk to steal his transformer.
As you work more on the case, you eventually come to the conclusion that Tesla is actually innocent. At the last second of the train's traveling, you realize that Moreau is the thief upon rechecking her suitcase. As the train stops, Moreau reveals her true plan: to sabotage the Ferris Wheel, so that the Chicago World's Fair won't be better than the Paris World's Fair. She races away with the transformer, with you hot on her tail. She quickly manipulates the Chicago Police to go after you, but you outsmart them and chase Moreau onto the Ferris Wheel, just as thunder and rain rolls in. On the Ferris Wheel she throws a box at you, and even tosses the Transformer off in order to get rid of both you and it, but you swing through a rope and grab it before it gets destroyed. When you finally corner Moreau at the top of the Ferris Wheel she warns you to stay back, but a close lightning strike causes Moreau to lose her balance, and she falls into Weisz's water tank. Most likely, she is then brought to jail.
- Moreau doesn't know how to swim, as mentioned when she is in the water tank.
- She is one of the only villains that does not appear on Super Villain Island.