Buckingham was sprawled on his chair behind his grand desk listening to his chaplain reading prayers, playing idly with a gold chain, his dark eyes veiled. When he saw John his face lit up. ‘It’s my wizard, John!’ he called. ‘Come in, my John! Have you made the water flow backwards up the hill for me?’

‘There’s a man here come in haste from the king,’ John said shortly, and pushed the messenger into the room.

‘You’re to go to Theobalds,’ the man blurted. ‘The king is sick with ague and asking for you. He says you’re to come to him at once.’

There was a sudden alertness about Buckingham, like the sudden freezing when a cat sees its prey, and then he moved.

‘Get me a horse.’ Buckingham started from his desk. ‘John, get one too. Come with me. You know the way better than any. And a man to ride with us. How bad is he?’ he threw over his shoulder to the messenger.

‘They said more sorry than sick.’ The man trotted after him. ‘But commanding your presence. The prince is already there.’

Buckingham ran up the stairs and looked down at John. His face was alight with kindled ambition. ‘Perhaps now!’ he said, and turned into his room to change his clothes.

John sent orders for horses to be made ready and sent a man running to the kitchen for a knapsack of food and a flask of drink. He sent no message for Elizabeth. The urgency of the young duke, the call of the adventure and the sense of living in great times was too much for him to remember his domestic ties.

When the duke came clattering down the front steps, handsome in his riding boots and a long cape, John was mounted on one good horse, and holding another. The servant who was to ride with them was coming from the stable yard.

The duke glanced at John. ‘Thank you,’ he said, and meant it.

John grinned. The great fault of these large households was their slowness. Meat was always eaten half-cold, hunting expeditions had to be planned days ahead and always started hours after the time named. Nothing could be done on impulse, everything had to be prepared. John’s ability to get a horse from the stables, groomed and ready to ride in minutes was one of his greatest talents.

‘Will you be all right to ride?’ Buckingham asked, glancing at John’s borrowed breeches and boots.

‘I’ll get you there,’ John said. ‘Never fear.’

He led the way at a steady trot out of the courtyard, put the cold sliver of the rising moon on his right and rode due west to Waltham Cross.