She does it now, in fact, as she navigates the piles of frozen slush to the Tiergarten in her patched coat of brown wool, her creased, ancient shoes. Some habits you can’t break. Though you wouldn’t know it from looking at her—in fact, you wouldn’t look at her to begin with, because Ursula’s an expert at passing beneath your notice, hunching her wide shoulders and sturdy frame, practically melting into the pavement and the shop windows and the lampposts—Ursula’s examining every forehead, every chin, every pair of eyes that passes by. From beneath her eyelashes she rakes in each detail of her surroundings and records it to memory.

Oh, her memory. There it goes again, taking a snapshot of this woman on the corner, aged about sixty-five, skeletal, threadbare gray coat, pale, narrow eyes, who might be a bank teller or a manager at a munitions factory or a Gestapo agent. Always Ursula has had this tremendous power of recollection, this capacity for storing and retrieving information, human faces especially—it’s what’s kept her alive these past four years, while committing endless acts of treason right here in Berlin beneath the very noses of the Gestapo. Longer than that, even. Since before the war. When the Nazis came to power and passed their laws, many of her Jewish friends began to disappear, so that it was natural to try to help them out of Germany, using her drawing skills to forge documents and so on, a hobby that became a vocation when the war came and one of her old lovers, an Englishman who had been studying in Berlin before the war and now worked for the British intelligence agency, the so-called Special Operations Executive, recruited her as an agent for the German section. It turned out that, in addition to her prodigious memory, she had a knack for subterfuge, an amoral willingness to sleep with any man or woman who might further her cause (or else kill him, as necessary), a feral bravery when it came to crossing forests and hayfields and alleyways in the dead of night. In short, she was a natural.

And just where has it got her?