'Was there a third point?' asked Butler innocently.
'Yes,' said Artemis, a touch testily. Still no sign of the individual he was expecting. 'I was about to say that if there is a gunman on one of these buildings, it's that one directly to the rear. So you should stay behind me.'
Butler was the best bodyguard in the business, and even he couldn't be a hundred per cent sure which rooftop a potential gunman would be on.
'Go on. Tell me how you know. I know you're dying to.'
'Very well, since you ask. No sniper would position himself on the rooftop of Casa Mila, directly across the street, because it is open to the public and so his access and escape would probably be recorded.'
'His or her,' corrected Butler. 'Most metal men are women these days.'
'His or her,' amended Artemis. 'The two buildings on the right are somewhat screened by foliage, so why handicap yourself?'
'Very good. Go on.'
'The cluster behind us to the left is a group of financial buildings with private security stickers on the windows. A professional will avoid any confrontation he is not being paid for.'
Butler nodded. It was true.
'And so, I logically conclude that your imaginary sniper would pick the four-storey construction to our rear. It is residential, so access is easy. The roof affords him or her a direct line of fire, and the security is possibly dismal and more than likely non-existent.'
Butler snorted. Artemis was probably right. But in the protection game, probably wasn't nearly as comforting as a Kevlar vest.
'You're probably right,' admitted the bodyguard. 'But only if the sniper is as smart as you are.'
'Good point,' said Artemis.
'And I imagine you could put together a convincing argument for any one of these buildings. You just picked that one to keep me out of your line of vision, which leads me to believe that whoever you're expecting will turn up outside Casa Mila.
Artemis smiled. 'Well done, old friend.'

The Lost Colony, Chapter 1