Artemis rooted through his backpack for the video cube. Though the box did actually play a computer game, its primary function was an X-ray panel with real-time viewing. The X-ray panels were in common usage among the upper criminal echelons, and it had been a relatively simple matter for Artemis to disguise one as a teenager's toy.
Artemis activated the X-ray, sliding it across the door of the deposit box beside Butler's.
The bodyguard had rented his box two days after Crane and Sparrow. It stood to reason that the boxes would be close to one another, unless Crane and Sparrow had requested a specific number. In that case it was back to the drawing board. Artemis reckoned that this first attempt to steal The Fairy Thief had a forty percent chance of success. These were not ideal odds, but he had no option but to 
go ahead. At the very least, he would learn more about the bank's security.
The game cube's small screen revealed that the first box was stuffed with currency.
'Negative,“ said Artemis. ”Cash only.“
Butler raised an eyebrow. “You know what they say; you can never have too much cash.”
Artemis had already moved on to the next box.
'Not today, old friend. But let's keep up the rental on our box, in case we ever need to return.“

The Opal Deception, Chapter 2