‘But it’s the same as the bloody one we already had,’ protested Macmillan, starting to lose his cool.
‘According to our simple surgeon, they are,’ said Steven. ‘But they can’t be. I keep saying this but we’re missing something.’ He picked up the two donor reports and looked at Macmillan. ‘Let’s go through these with a fine-tooth comb, even if it takes us all night.’
Macmillan only took a moment to concede. ‘Why don’t we use the audio visual equipment in one of the seminar rooms?’ he suggested. ‘If we see the test results side by side up on a screen, one of us might spot a difference more easily. It’ll be better than sifting through masses of meaningless letters and numbers at a desk all night.’
‘Good idea,’ agreed Steven. ‘But we don’t have the reports on disk, only hard copy.’
‘Then let’s do things the old-fashioned way,’ said Macmillan. ‘There’s an overhead projector in S12.’
THIRTY-SIX
The two men made their way to seminar room S12, an ‘inside’ room with no windows and a semicircular tier of seats facing a flat front wall, fronted by a desk, a few chairs and a lectern. Steven set up the overhead projector while Macmillan moved the lectern to one side and pulled down a projection screen from its ceiling mounting. Steven placed the first page from each of the reports side by side on the projector’s glass platen and adjusted the focus until the text became sharp.
The reports had been prepared using different formats so it wasn’t possible to match up all the pages, but the first page of each showed the major compatibility tests and it didn’t take long for Steven and Macmillan to agree that there were no discrepancies. After that, it became progressively more difficult when the order of the tests started to vary. An hour and twenty minutes had passed before Steven murmured, ‘Hang on…’
‘Spotted something?’
‘Fourth line from the top in the section headed “Co-receptors”, it says CCR5 — /- in Louise’s analysis, but in the other one I’m pretty sure it said…’ Steven paused to change one of the sheets on the platen. ‘Yes. Look there, in the Sci-Med lab report it says CCR5 +/+.’
‘It is,’ agreed Macmillan. He stared at the screen for fully thirty seconds before asking, ‘Any idea what it means?’
‘None at all, but it is a difference.’
‘It is,’ sighed Macmillan, rubbing his eyes. ‘And, right now, it could be our needle in the haystack. I suggest we complete the comparison to see if we can find any others before we call in the boffins.’
Thirty minutes later both men were in agreement that there was only the one difference in the lab reports. The sound of the projector fan faded and Steven brought up the room lights.
Macmillan said doubtfully, ‘Can that really be what this is all about?’
Steven felt inclined to share his doubts but said, ‘I guess we won’t know that until we understand what it means.’
‘Let’s talk to our own lab now,’ said Macmillan. ‘See what they have to say about the difference.’
‘It’s Saturday evening,’ Steven pointed out.
‘If what you suspect about Porter-Brown is true, time’s not on our side. Get the duty man to call out Lukas Neubauer. I want him here tonight. Tell him to try for eight o’clock.’
Dr Lukas Neubauer, head of the biological section of Lundborg Analytical, seemed unfazed at being called out on a Saturday evening. When Steven mentioned this, he replied, ‘Arsenal lost today; what more is there to live for?’
‘There’s always next season,’ said Steven with a sympathetic smile, knowing that Arsenal’s hopes for the Premier League title had all but gone. ‘With the amount of money Sci-Med are putting your way at the moment you can probably buy them a new striker.’
The banter stopped when Macmillan entered the room and thanked Lukas for coming, apologising for the timing. He explained what the problem was and handed Lukas the two reports.
‘The discrepancy seems to be in something called CCR5,’ said Steven. ‘You give it a double plus while the other lab says double minus.’
Lukas, a tall, Slavic-looking man in his mid-forties, pushed his glasses up on to his forehead while he compared the two documents, holding them both up close to his face and alternating between the two. Steven, who had always got on well with him, thought he looked like an eagle contemplating his dinner as his eyes moved sharply to and fro. He knew that nothing much got past Lukas Neubauer: he was a born scientist who had to know how everything worked and how everything related to everything else.
‘Interesting.’
‘First, can you tell us what CCR5 is?’ asked Macmillan.
‘It’s a co-receptor on the surface of human T4 cells,’ replied Lukas, continuing to read the reports.
‘Uh-huh,’ said Macmillan, implying that he was still waiting for an answer to his question — one he could understand.
‘The important thing from a human point of view is that viruses use it to gain entrance to human T4 cells,’ said Lukas.
‘What would its relevance be in a bone marrow transplant being carried out to help a leukaemia patient?’
‘None at all.’
Steven felt encouraged. That would fit with what Mary Lyons had told him about Louise noticing something but she and Monk agreeing that it wasn’t relevant. But he’d still gone on to kill her because she’d noticed it.
‘I take it the plus signs mean that your lab found CCR5 to be present while the other lab didn’t?’ said Macmillan. ‘A mistake on someone’s part?’
‘I don’t think so,’ said Lukas after a few moments of deep thought. ‘I don’t think so at all… You see the two plus signs? It means that we found the donor to have inherited the CCR5 factor from both mother and father. The other lab, however, has reported a double minus, which means that the donor would have no CCR5 at all. They had inherited a lack of this receptor from both their mother and father, not a common occurrence. Homozygous, we call it. There’s actually a name for this negative mutation, by the way. It’s called Delta 32.’
‘Does this lack of CCR5 have drawbacks?’ asked Macmillan.
‘Not as far as we know, but it does have distinct advantages. Delta 32 individuals are immune to certain viruses — the viruses can’t get inside their cells. I don’t suppose it has any relevance here, but there’s also a connection with research into Black Death.’
‘Of course,’ said Steven, suddenly remembering the precis of John Motram’s research he had read in the file Jean Robert had prepared for him at the start of the investigation. ‘It was the Delta 32 mutation that changed in frequency in the European population after Black Death struck.’
Lukas nodded. ‘It seems it was a huge advantage to be Delta 32 at the time.’
‘This was the basis of John Motram’s research,’ said Steven. ‘The fact that Delta 32 made you immune to Black Death suggests that it was caused by a virus and not bubonic plague. He’s an expert on Delta 32.’
‘Which may be why he was invited on to the transplant team in the first place, if what we’re seeing here is anything to go by,’ said Macmillan, seeing another piece fit the puzzle.
‘So’, said Steven, turning to Lukas, ‘if Louise says the donor was Delta 32 and you say he wasn’t… which one of you is right?’
‘Both of us,’ said Lukas.
Steven and Macmillan looked at each other as if struggling to keep up. ‘You can’t both be right,’ said Steven.
‘Yes we can… if the samples came from different people,’ said Lukas. ‘That’s my guess.’
‘Just when I thought we were making progress…’ said Macmillan.
‘But I saw the samples divided up myself,’ said Steven. ‘I watched Louise Avery do it. She kept one set; I brought the other set back for you.’
‘The airport,’ said Macmillan suddenly. ‘The samples were taken from you at Heathrow Airport. They were out of your possession for several hours.’
Steven rubbed his forehead as he thought about that. ‘But if you’re suggesting the samples were swapped before they gave us them back for analysis, it implies they already had samples from someone else… who was also a perfect donor for Patient X…’