With two bags each, the foursome crossed a busy road and caught the smell of the sea as they made their way towards the passenger terminal. The building was long and low, with floor to ceiling windows, counters for buying tickets and a roped-off area that led to a customs post where French officials inspected documents and stamped passports. From there, passengers passed on to the dockside and up the gangplanks to board the ship.

As Henderson led the three children inside the building, he looked out and saw a net filled with baggage being hoisted up by a deck crane and one of the two gangplanks being drawn aboard the ship.

‘Tickets and passports at the ready, sir,’ a steward said in English. His hat bore the name SS Cardiff Bay and his Mancunian accent made Henderson feel a little closer to home, but his stomach churned, because the ship was about to leave.

‘We’ve just got here,’ Henderson gasped, as he retrieved his passport and wallet from a briefcase. ‘I need four tickets.’

At the same time, Rosie had found Paul’s passport and her own.

‘John,’ the steward shouted, ‘what’s the passenger count?’

‘There’s a few cabins and plenty of seats.’

Henderson smiled. ‘I was worried that you might be full.’

The steward shook his head. ‘If you’d been here a week back you’d have seen a right scrum. But the Government laid on some extra boats and we’re just picking up stragglers now. I tell you what, since we’re about to leave, I’ll let you pay the steward on board. Be sure that you do, mind.’

Henderson nodded. ‘Of course. Thank you, sir.’

The steward waved them on to the next counter, where a more senior crewmember stood waiting to inspect the passports.

‘I only see three,’ he said, raising an eyebrow and glancing at Marc.

‘His father was killed in an air raid, the documents were all destroyed.’

‘I’m sorry, sir, but we have strict regulations to prevent German agents from entering Britain. Every passenger must have proper documentation.’

‘But he’s just a child,’ Henderson spluttered.

‘I know what you’re saying sir, but rules are rules. Especially in wartime. You’ll have to apply for a passport from the consular office in town. It opens at nine tomorrow.’

Marc didn’t understand English and had to ask Rosie to explain what was going on.

‘When will the next boat be here?’ Henderson asked.

‘We’re the only boat running this route now,’ the officer said. ‘If things go to schedule, we’ll be back here Tuesday morning and set to sail Tuesday afternoon.’

Henderson tried to think fast. He knew there was no point trying to throw his weight around, because as a spy he carried no documentation that proved his rank. He felt a tug on his sleeve and saw Marc look up at him.