‘Ah, here we are – Das Bayerischer Haus.’

The restaurant was on Donhoff Strasse, close to where it joined Kommandantenstrasse. It had been a ten-minute stroll from the hotel, one that would have been quite pleasant had Otto not spent much of it glancing ominously up to the sky. ‘There’s no moon and no clouds tonight; your RAF like to bomb Berlin without those distractions. If a raid starts before we reach the restaurant, I think it would be better to head back to the hotel. Make sure you keep your pass safe.’

The passes had been issued to them by the hotel, confirming they were registered guests, giving their names and the dates of their stay and declaring they were allowed to be out and about in the Mitte district until nine thirty – ‘precisely’ – that evening. They had an impressive array of stamps, including one at the top with a large swastika.

At the entrance, Otto stepped back and gestured for Prince to enter first. Once he was inside, he turned round. Otto was still holding the door open, this time for a woman on her own. It was unquestionably the woman from the hotel, now wearing a beret with a single feather set at an angle on the side of it. She glanced in Prince’s direction, her darting eyes connecting with his for the briefest of moments, and had it not been so dim in the restaurant, he’d have sworn she smiled.

As they were shown to their table, he wondered whether he should mention her to Otto but thought better of it. Otto would probably wonder if he was deluded. An agent in enemy territory overcome by paranoia. Not unheard of.

In any case, it was almost certainly a coincidence: a guest at the same hotel who he’d bumped into a couple of times, now in the same restaurant as them. Nothing unusual.

What happened next was very much as Otto had described from his first visit to the restaurant. The ground floor was busy and the tables were packed closely together. With the windows covered by blackout material, the interior was quite gloomy, making it hard to see much around them. A tall waiter with a nervous tic showed them to a table for two by the stairs and provided them with a menu. Prince looked round and noticed that the woman was sitting on her own at a small table by the door, her back to them, facing the window. He had barely had a moment to study her when the harassed-looking maître d’ appeared. He was terribly sorry, but there had been some confusion over bookings, for which he could only apologise: it was his fault. He would need their table to join to another one to accommodate a booking of four people. But he did have a room upstairs. Perhaps they’d find it more comfortable up there anyway?