David Copperfield's Orient Express

The following 9 cards represent nine cars on the Orient Express. You may start in the Shower, Diner, Club, or Mail cars. You may move one step up, down, left, or right. You may not move diagonally.

Step #1	Make four moves.
	You couldn't be in the Staff car, so remove it.
Step #2	Make five moves.
	You couldn't be in the Club car, so remove it.
Step #3	Make two moves.
	You couldn't be in the Mail car, so remove them.
Step #4	Make three moves.
	You couldn't be in the Baggage or Caboose cars, so remove them.
Step #5	Make three moves.
	Since many of you just left the Shower car, remove it.
Step #6	Make one move.
	You are in the diner car.

Your assignment is to explain why this magic trick works. Some suggestions:

• Number the cards (Bar = 1, Shower = 2, Baggage = 3, ... )
• Which numbers can you start on? What do these numbers have in common?
• Do the trick several times, recording the numbers of the cars you visit, and the ones you remove.
• How can David Copperfield be sure you're not in the cars he tells you to remove?

Write an explanation of how this magic trick works. Make your explanation clear enough that anyone could read it and understand how this magic trick works.