Ballroom 1

Luigi unlocks the door to the room with the white figure from earlier and walks in, finding nothing but the Dancing Whirlindas. Since the dancing ghosts are distracted with dancing, they're relatively easy to catch, but Luigi decides to search for the ghastly white figure.

He shakes every piece of furniture in an attempt to find it, but only manages to find a small white ball with a Boo's face on it. In a fit of rage, he tosses the ball at the painting on the wall, and to his shock it goes right through. He climbs up onto a sofa and reaches through, and gets grabbed and pulled through.

Continue.