She used a different dead letter drop for her messages. It was ten minutes’ walk to the church, which was closer to where she lived than she’d have liked, but its doors opened early and closed late, meaning she could go there at more or less any time. By seven o’clock there were already a dozen or so worshippers, but the morning service had yet to start, so they were scattered around the large seating area. Her preferred pew towards the back was unoccupied; she sat down and allowed herself five minutes of apparent prayer and contemplation before giving one final look around, then removing the plain envelope from her handbag and placing it inside a prayer book. She remained sitting for another five minutes until she spotted an elderly woman a few rows in front get up to leave and decided to follow her.

From there she caught a tram towards the Assistens cemetery, getting off one stop after it, stopping at a news kiosk to buy a paper and check she hadn’t been followed before doubling back.

She left her chalk marks on one of the same graves as Weston’s courier used. She often wondered how wise this was, and she also questioned the sense of having to carry a bit of chalk in her handbag. How, she’d once asked Weston, would she explain that away? He’d patted her on the knee and told her he was sure she’d think of something. His courier would walk past in the next day or two. She had no idea who he or she was, or how they managed to get her messages to Stockholm for Weston to encrypt before transmitting them to London.

She did think she’d spotted one of his couriers a few months previously. It was a Monday lunchtime and she was walking through the cemetery to check the graves when she saw an elegantly dressed man, perhaps in his late sixties, walking ahead of her with a dog. He’d paused in front of one of the three graves and taken a step towards it before turning to check no one was around. When he saw her, he moved back onto the path and walked away in the direction she was coming from. For a brief moment their eyes met, perhaps with a fleeting understanding of what the other was doing there. Hanne saw him hesitate before carrying on, and she felt an irrational urge to run after him and say something, to have a word with someone who’d understand.

Espionage was not only tiring, it was also very lonely.