Sian Clifford as Diana Ingram, Matthew Macfadyen as Charles Ingram and Michael Sheen as Chris Tarrant in ‘Quiz’

The miniseries Quiz, now showing on ITV, tells the story of Charles Ingram, the British army major who won a million pounds on Who Wants to Be a Millionaire? in 2001 but was later accused of cheating: an ‘accomplice’ among the waiting contestants, Tecwen Whittock, was said to have communicated the right answers by coughing. In 2003, Ingram, his wife and Whittock were found guilty of ‘procuring the execution of a valuable security by deception’. Quiz is based in part on a book written by my husband, James Plaskett, and the late Bob Woffinden.

James had himself been obsessed for years with getting on Who Wants to Be a Millionaire? I coached him along the way. Every birthday and Christmas I gave him quiz books. We still have a couple of shelves of them. He got as far as the studio several times but was lagging on the ‘fastest finger first’ test, so I rigged up a little board with several light switches screwed to it. That seemed to help.

He had long been convinced of the Ingrams’ innocence, and had been to visit them by the time he got into the hot seat in 2005. One of his questions had Avebury as the answer and he only knew it because he had passed it en route to meet the major, a curious coincidence. He was already known as a defender of the Ingrams, so kept off the subject when talking to Chris Tarrant.

I was at home in Spain, on stand-by as his phone-a-friend lifeline. I had been told to be at the ready for three-quarters of an hour. When this time passed, I made myself a large sandwich and took a bite. At that moment, the phone rang, and it was Chris Tarrant. I quickly spat out the food and answered. The question was about the patron saint of shoemakers. Saints were one of the things I had advised James to learn but he hadn’t got round to them. I was unsure but thought it was probably St Crispin. I advised him to use another lifeline. In fact, he used both the remaining ones.

It was shortly after my birthday in November 2005 that James came home with a cheque for £250,000, post-dated to February 2006 when the show would be broadcast. I advised him to tell nobody and thought we ought to keep our expenses low until the money was actually in the bank. The Ingrams had also received a cheque before the court case. The money was taken away from them. James had been accompanied by his friend Stuart Conquest in the audience. Stuart, like James, is a chess grandmaster. They had been treated with a little bit of suspicion. If the production company took against coughers, what would they think a couple of grandmasters might get up to? Stuart was taken out of the studio towards the end, just in case.

James came home with no card and no birthday present for me but vague romantic statements of ‘half of what I have is yours’ which did not cut much ice as we did not have it yet. We quarrelled horribly for days as he at first threatened to give the lot to charity. I would definitely have divorced him if he had done that. I was quite happy for him to give 10 per cent to charity though. He gave it to Sense, the charity that Major Ingram was running for in the London Marathon.

The oddness of the experience of winning and our quarrels reinforced James’s view that the Ingrams were innocent. They also had been heard quarrelling. Good news can be as much of an upheaval as bad news.

Most of the evidence against the Ingrams hinged on Whittock’s coughing and that always seemed weak to me. Sometimes a cough is just a cough. It’s interesting that Quiz is being shown at a time when most of world is locked down at home trying not to catch a virus of which one of the earliest symptoms is bouts of coughing. James had planned to visit the UK for a preview of the series and a party. That of course never happened. The producers sent us a link in the cloud to watch it on.

A few weeks ago I was doing a part-time job teaching English and was suddenly struck with an involuntary cough set off by the synthetic smell of a board marker. The school secretary rushed in with a look of horror on her face and threw a cough sweet at me. At the moment, I am very unlikely to cough at all as the air has become remarkably clean because of the lack of traffic in the empty city.

Our lives changed at the time of the win, but it was 14 years ago. We have a house out of it at any rate. The rest of the money was gradually used up in the process of living. We were never very regular wage-earners, a writer married to a chess grandmaster. A quarter of a million sounds like huge wealth but perhaps it should just be thought of as the equivalent of a few years’ salary at a decent rate. As it is, we are now back to our usual Bohemian penury wondering how our own and everyone else’s finances will be resurrected when the coughing goes away and we are all allowed out again.