John went inland with the scouts and saw the French cavalry driven back and back over brackish fields of rough grass where a hundred, a thousand, red poppies blew. ‘Like soldiers in red coats,’ John said. He shivered as if it were an omen and bent to pluck a couple of the drying seed heads.

‘Still gardening, Mr Tradescant?’ one of the scouts asked.

‘They are a fine colour,’ he said. ‘A plentiful show.’

‘Red as blood,’ the scout said.

‘Yes.’

The English luck held. Within days Buckingham held the whole of the little island of Rhé and the French army was holed up in one tiny half-finished castle on the landward side: St Martin. John was sent to spy out the lie of the land.

‘Tell me what their fort is like, John. Give me an idea of the size and how strong it is,’ Buckingham commanded, as he strolled down the lines and came across Tradescant, digging a little nursery bed for any rare plants he might find during his stay. ‘Leave gardening, man, and tell me how their fort is placed.’

John put his trowel to one side at once, and slipped his satchel on his back, ready to set out.

‘I’m no engineer,’ he warned Buckingham.

‘I know that,’ his lord replied. ‘But you’re careful and you have a good eye, and you have been in a siege and under fire, which is more than can be said for any one of us. Go and have a look and when you come back, come to me privately and tell me what you think. I can’t trust a word these Frenchmen speak. All they want is victory at whatever price, and that price would include me and they would still pay it gladly.’

John nodded. He did not ask what, in that case, they were doing there, camped on a French beach on a small island off France. It was not his nature to complain of the obvious. He took up his blackthorn stick and set off, along the beach towards the other side of the island. Buckingham watched him go and noted the limp which favoured John’s aching arthritic knee.

He was back late in the evening, with a brace of cuttings and a rough sketch.

‘Good God, what have you in your hat?’ Buckingham demanded. He was seated before his tent, at a table of exquisite marquetry, looking young and careless with his white linen shirt undone at the throat, and his hair tumbling in black curls about his shoulders.

John carefully took one of the plants by the leaf and held it up. ‘It’s a new sort of gillyflower,’ he said. ‘I’ve never seen such leaves before.’ He held out the plant. ‘Do the leaves have a scent?’

Buckingham sniffed. ‘Nothing I can smell, John. And – forgive me – but you were sent out as a scout to bring us news of the French fortification, not to go plant-gathering.’