There were probably other details that looked correct at first glance but would be fake.

If this pack was referred back to VirtuBank’s team in Chennai to be double-checked, it would be obvious it was fake.

His task would be to get this into the bank and ensure it didn’t get detected during testing or documentation and referred back for any reason.

The first problem was the software had to just turn up on-site and get installed. It wasn’t a download from the patch site. It bypassed that whole system and he needed a cunning excuse to have it accepted on-site. The first thing he would have to do was come up with that excuse.

Every year, Richard put a large advert in the local newspaper back in Glasgow. The advert was designed so that as few people as possible would be interested: fire-damaged goods; water-damaged furniture; second-hand (and obsolete) electronic goods. For sale to trade only. He put his own phone number as the contact. If anyone did happen to be interested in the advert and rang him, he would apologise and explain that someone had already agreed to buy the whole lot. He never had to apologise to very many disappointed customers.

The adverts were placed on one of these days – January 25th, April 25th, July 25th, October 25th – so they would be easy to track. The method of passing messages was very simple. Richard could write anything he wanted to make the advert look genuine. The messages hidden there were decoded using serial numbers that were part of the advert itself. Therefore, so long as he had all the letters of the alphabet somewhere in the wording, he could send any message just by “pointing” at the letters using his serial numbers. It was that simple in principle. The serial numbers printed on the advert had to be transformed using a mapping algorithm, but it was still a simple technique. It would be easy for an expert to decode. But why would anyone ever suspect these adverts were not genuine? They would surely never come to the attention of any decoding expert.

Starting on July the previous year, he had put adverts in on every possible day. The more often he placed the adverts, the more paranoid he was that he would expose himself. Nevertheless, he was really convinced he was in the right place at the right time by now, and he was surprised no one had reacted yet. His messages had become ever more urgent. His last message read: “Still at VirtuBank. Opportunities with access to main servers at several major financial customers.” His full contact details were there as usual.

He had checked his coding and decoding again and again, wondering if he had made a mistake, so convinced was he that he should have been contacted this time. There was no mistake. He had posted that last message to the paper three months ago but had still been ignored. He had expected an immediate response.

Every time this had happened, he had gone through the same feelings. Elation in placing his advert. Anticipation while waiting for a reply. Disappointment that, yet again, nothing had happened. Each time the disappointment was more numbing, the possibility of ever doing anything more remote.

This time he had been so disappointed that he had not bothered to repeat his message on 25th October, 2013. Yet that was the time when they finally reacted.

Richard remembered, sometime in the mid-eighties, walking up and down the rows of gravestones looking for his father’s headstone one sunny day in the hills near Milngavie. His dad had died suddenly, of a heart attack. Richard was on holiday in France when it happened. No one had managed to contact him, and the funeral had to go ahead without him. He flew up from London as soon as he could and found the stone where he laid flowers a few years previously. Now both his parents’ names were inscribed.