Conor wandered between these columns of knowledge, almost touching everything, but holding back, knowing somehow that another man’s dreams should not be disturbed.

Suddenly he froze. There was something he should do. The chance may never come again.

‘I must capture the flag,’ he breathed. ‘That’s what a pirate captain is supposed to do. Go to the roof, so I can capture the flag and gloat.’

‘Capture the flag and goat?’

‘Gloat.’

Isabella stood hands on hips. ‘It’s pronounced goooaaat, idiot.’

‘You’re supposed to be a princess. Insulting your subjects is not very princessy.’

Isabella was unrepentant. ‘Princesses do what they want – anyway we don’t have a goat on the roof.’

Conor did not waste his time arguing. There was no winning an argument with someone who could have you executed. He ran to the roof door, swishing his sword at imaginary troops. This door, too, was open. Incredible good fortune. On the hundred previous occasions he and Isabella had ambushed King Nicholas, every door in the palace had been locked, and they had been warned by stern-faced parents never to venture on to the roof alone. It was a long way down.

Conor thought about it.

Parents? Flag?

Parents? Flag?

‘Some pirate you are,’ sniffed Isabella. ‘Standing around there scratching yourself with a toy sword.’

Flag, then.

‘Arrr. I go for the flag, hostage princess.’ And then in his own voice, ‘Don’t touch any of the experiments, Isabella. ’Specially the bottles. Papa says that one day the king is going to blow the lot of us to hell and back with his concoctions, so they must be dangerous.’