It is so that you can see and know all the passengers and get the items you may need.
This is done by-
There are at least 9 cars in the train, not including the locomotive and coal car. You must meet all of the passengers before Edison will show you his invention in his cabin. (See passengers and crew in boldface below)
After seeing the Conductor and Coal man, go left to each car. The first car is the sitting car. Meet the builder of the Chicago Fair's giant ferris wheel, George Ferris, Jr., who has received word that the wheel does not have sufficient power to work. The second car has compartments for Nikola Tesla , suffragette Susan B. Anthony, and a young man named Erik Weisz (some may recognize the name). You cannot enter Tesla's room at first. Ms. Anthony gives you a PAMPHLET on voting rights for women. You meet Gustav Eiffel, builder of the Eiffel Tower four years earlier. You meet Weisz, then pass the Water Closet (toilet). The third car has the Porter closet and baggage for the riders. The fourth car has an unlabeled compartment, probably for the New York Times reporter standing outside. It also has those of Mark Twain, Thomas Edison, and a French woman reporter named Moreau. First you talk to the Times reporter, who is critical of Chicago. In his cabin, Twain is a bit ill from the train fumes. You pick up a PENCIL from a table enroute to Edison's cabin, and he asks you to come back later. In Moreau's room, you collect an issue of her Paris NEWSPAPER LeMonde which shows the 1889 Paris Exposition and the Eiffel Tower. The fifth car is the Dining Car, where you meet the Porter (if your avatar is female, so is the porter). The sixth car is an open flatcar with some hay bales. The seventh car is the reverie lounge, the multiplayer room for the island. The eighth is baggage and freight, including odd items from other Poptropica islands. The ninth (last regular) car is occupied by a Pinkerton Detective and you are brusquely turned away.
Read more: How_do_you_beat_Mystery_Train_Island_on_Poptropica
The 21st island on poptropica will be mystery train island.
Mystery train island
It was revealed in late July, 2011 that the 21st Poptropica island would be Mystery Train Island.
Search up "How do you beat Time Tangled Island"
Go to Mystery Train Island and go to the left side of the train and talk to Edison. He needs help carrying his bags onto the train. Arrange the bags from shortest to tallest, then click on the board. Edison invites you to join him on the train and you accept and start a whole new mystery!
You have not met and talked to "everyone" or Edison would set up the camera. You need to see each person, including the guard at the back of the train (far left). There are the 4 crew and 9 passengers including Edison.
in the porters closet
HJ
In the janitors closet
One of the requirements of the quest is that you initially visit with each of the passengers. Sometimes just speaking to almost all will be enough. Don't forget the coalman, or the Pinkerton man at the rear of the train.
Mademoiselle Repertor Chick, left of edison
The thief is the French reporter.