Luigi's Mansion: Dark Moon - E-3 A Train to Catch

After Luigi and E. Gadd inspect the security camera image the Toads brought back, they find that the sack the Boos have been carrying around this whole time has Mario trapped in a painting, and that King Boo has been the one behind the Dark Moon's destruction. Luigi heads off to try and access the Train Exhibit. However, he gets held up when a Strong Poltergeist steals what he needs to enter. Found all the remaining 8 gems and the boo in this level. There's a bonus boss you have to fight in the space exhitit.