It has been requested that this article be rewritten. Reason: not done yet
E-3: A Train to Catch is the third mission of the Treacherous Mansion in Luigi's Mansion: Dark Moon.
Plot
E. Gadd tells Luigi that one of the Toads from the previous mission has got a security image (which he explains that he had to fix it) and they should have a look at the image.
When it is first looked at, Luigi looks at the portrait the Boos have been dragging all over the valley, it is shown this is Mario, who has been captured and brought to the Train Exhibit. They both look at the security image. Before the player is done looking at it and presses the B button, E. Gadd tells them that one of the Boos is extremely different to the others.
When they zoom in at this Boo, it is revealed to be King Boo, who scares both of them and jams the security image.