Butler’s. The bodyguard had rented his box two days after Crane & Sparrow. It stood to reason that the boxes would be close to one another, unless Crane & 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 per cent 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 next box contained legal papers tied together with ribbons. The one after that was piled high with loose diamonds in a tray. Artemis struck gold on the fourth box.

Figuratively speaking. Inside the deposit box was a long tube containing a rolled-up canvas.

‘I think we have it, Butler. I think this could be it.’

‘Time enough to get excited when the painting is hanging on the wall in Fowl Manor. Hurry up, Artemis, my arms are beginning to ache.’

Artemis steadied himself. Of course Butler was right. They were still a long way from possessing The Fairy Thief, if indeed this painting was Herve’s lost masterpiece. It could just as easily be some proud grandfather’s crayon drawing of a helicopter.

Artemis moved the X-ray machine down to the bottom of the box. There were no manufacturer’s markings on the door, but often craftsmen were proud and could not resist placing a signature somewhere, even if nobody but them knew it was there.

Artemis searched for maybe twenty seconds before he found what he was looking for.