From The New Yorker:
The plan isnâ€™t foolproof. For it to work, certain things must happen:
â€”The door to the vault must have accidentally been left open by the cleaning woman.
â€”The guard must bend over to tie his shoes and somehow he gets all the shoelaces tied together. He canâ€™t get them apart, so he takes out his gun and shoots all his bullets at the knot. But he misses. Then he just lies down on the floor and goes to sleep.
â€”Most of the customers in the bank must happen to be wearing Nixon masks, so when we come in wearing our Nixon masks it doesnâ€™t alarm anyone.
â€”There must be an empty parking space right out in front. If it has a meter, there must be time left on it, because our outfits donâ€™t have pockets for change.
â€”The monkeys must grab the bags of money and not just shriek and go running all over the place, like they did in the practice run.