Craig Russell - The Valkyrie Song

… particularly what he did to women. I tell you, I saw more than my fair share of beasts out there, and Vuja i c was right up there with the worst of them. Unfortunately it’s not always about who deserves justice most, but about who you can get the evidence on. Vuja i c was such a cunning little bastard that we never had anything more than rumour on him. It’s not a very policeman-like thing to say, but when he got topped my first reaction was that he got what he deserved. The only pity is that he didn’t suffer the same way the people who fell into his hands did.’

Fabel nodded, watching Lange. There are some things, he thought, even in this job, that it’s better not to see. To know. At that moment he knew he was talking to someone whose dreams were even darker, even more terrifying, than his own.

‘Thanks, Michael,’ said Fabel. ‘If anything else comes to mind, please let me know.’

Fabel and Karin Vestergaard had just stepped through the revolving doors and into the bright double-storey reception atrium of the Police Presidium in Alsterdorf when they were stopped in their tracks by a determined-looking Anna Wolff.

‘Don’t take your coats off,’ she said, with a grin. ‘We’ll take your car, Chef. I’ll give you directions. There’s someone I want you to meet…’

The cafe Anna took them to was in the Sachsentor pedestrian zone in Hamburg-Bergedorf. When they arrived, a young woman with a pretty but rather severe face and long dark hair was waiting for them. Sandra Kraus sat with a huge canvas bag at her side, the strap still over her shoulder, and tapped the cafe table with the tips of her fingers as Fabel, Vestergaard and Anna approached, almost as if she was announcing their arrival with a drum roll. She didn’t stand up but smiled at them. Fabel noticed that it was like when Karin Vestergaard smiled: nothing of it seemed to reach the eyes.

‘I’ve known Sandra since we were kids,’ said Anna after she had done the introductions. ‘She was the smartest student in the whole school. And she is an absolutely brilliant cryptologist.’

‘Really?’ said Fabel with genuine interest but looking questioningly at Anna. He was slightly distracted as Kraus drummed her fingers again on the tabletop. He turned to her and found the intensity of her gaze disturbing, as if she was looking at him as an object rather than a person.

‘Yes — really,’ said Anna, with more than a hint of defiance. ‘And trust me, bringing you here to meet Sandra isn’t a waste of time. I gave her a copy of Muliebritas. The same issue we found in Drescher’s flat.’

‘Does she know…?’

Anna shook her head. ‘You told us to keep a lid on the Drescher thing and that’s exactly what I’ve done. Sandra only knows that we may have a coded message in this magazine. To be honest, that’s all she’s interested in.’

‘And did she find anything?’ asked Vestergaard.

‘It took her five minutes to find the message and crack the code. No more.’

‘Are you trying to tell me that an amateur cryptologist can break a code created by one of the world’s most successful secret police and espionage agencies?’ Fabel smiled patronisingly.

Kraus drummed her fingers on the table again, took a sip of her coffee and then spoke briskly. ‘I have advantages that they didn’t have. I have an inbuilt ability to recognise patterns in things. What you see as complexity, I see as structure and ultimately simplicity.’

‘There’s more,’ said Anna. ‘I got all of the issues of Muliebritas for the last three years. Drescher was using it regularly to communicate with the Valkyrie. Sandra has decoded dozens of messages.’

‘It really wasn’t that difficult. The person who called himself “Uncle Georg” in the announcements used a combination of polyalphabetic cyphers. Basically he used a Vigenere Square with a staggered shift of Caesar cyphers. Basic stuff. For example…’

She took a pad and pencil out of the huge shoulder bag and wrote ALTONABALKONSFOURTHIRTYPMTHURSDAY on the pad. Fabel noticed that Kraus’s handwriting was perfect, the capital letters corresponded exactly with the lines on the pad.

‘That becomes VLEYLRJEGKZXQWWYMTSSPKGTHT-SEPJLET,’ she continued. ‘Of course, a long jumble of letters like that would be very easily noticed by anyone looking at the magazine, and would attract the attention of any cryptologist, so he buried them in several personal ads throughout the announcements section. He put in thanks notices that listed names. The initials would give several of the encrypted letters in each announcement.’

‘And you’re absolutely positive that you have interpreted the codes correctly?’ asked Fabel.

‘Like I said, it was a simple enough encryption. In principle. But for three hundred years the Vigenere cypher was considered unbreakable simply because to decode the encryption you have to know which word was used as the keyword. In other words, what the vertical letters are on the axis of the Vigenere Square.’

‘And you worked it out?’ asked Fabel. ‘How?’

‘I just saw it. I have this knack for frequency analysis of letters and recognition of common pairings. I read all the messages and I could see the patterns. You’re only supposed to be able to do frequency analysis with monoalphabetic cyphers; not with a polyalphabetic cypher like this one where an encrypted letter can be decoded as more than one original.’

‘But Sandra can do it,’ said Anna with clear pride in her friend’s abilities. ‘Tell him the keyword, Sandra.’

‘Valkyrie,’ said Kraus, again drumming out the same tattoo with her fingertips on the tabletop. ‘The word used as the keyword was Valkyrie.’

As Anna drove back to the Presidium, Fabel sat in the passenger seat and went through the messages Sandra Kraus had decoded.

‘These are all times and places,’ said Fabel over his shoulder to Vestergaard, who sat in the back. ‘Obviously he passed anything sensitive on in person. This was just used to set up a meeting.’

‘So that means we can now do exactly the same,’ said Vestergaard. ‘We can lure this Valkyrie out into the open. Assuming she really doesn’t know about Drescher’s death.’

‘We’ve still got the lid tight on that, but for how much longer I don’t know.’ Fabel turned to Anna. ‘That’s an interesting friend you’ve got there.’

‘Sandra? She’s great. She has a genius IQ.’

‘I guessed that much,’ Fabel said, with a small laugh.

‘And she’s an Aspie.’

‘A what?’

‘Did you notice her drumming her fingers all the time? Same rhythm, same number of beats. Or how she’s got an unnerving way of seeking eye contact with you?’

‘As a matter of fact I did,’ said Fabel.

‘Sandra has Asperger’s syndrome. But she calls herself an Aspie. She doesn’t see herself as a sufferer from a disability. Just different, and she’s cool with that. She campaigns for a group that promotes neurodiversity… the idea that there is more than one type of mind. She calls us NTs — Neurologically Typical.’

‘I thought people with Asperger’s have difficulty with interpersonal relationships. You said she’s your friend…’ said Vestergaard from the back seat.

‘A good friend,’ said Anna. ‘Sandra has problems in some areas, but, as you could see, there are compensations in others. And she has taught herself coping strategies and stuff. I’ve learned not to judge. It’s funny: Sandra said that one of the stereotypes people have of Aspies is that they have little or no empathy for the feelings of others. That’s why it’s often difficult to recognise a male Aspie: who can tell the difference from a normal man?’

Vestergaard gave a loud laugh. Fabel shrugged.

‘Well, one thing’s for sure,’ he said. ‘Your friend Sandra has probably given us our biggest break in this case so far.’