This was the beginning of my digital education, and I discovered a whole world my husband had kept from me. I learned that there were ways into even locked phones, hacks and tricks and codes. Patrick’s was tied to his Gmail account, and he had left that logged in on the home computer, which I knew the password to, though I only used it to order shopping online. The Gmail account itself was blameless – nothing but circulars, advertisements and electronic receipts, and it struck me again how impersonal his life had been. Through the account, I was able to reset the lock screen on the phone. It must happen a lot nowadays, when so much of our lives is digital, locked up behind passwords. I also didn’t know the code for the air conditioning, or to adjust the alarm settings or even the smart TV. Never mind wills – this is what we should write down for our loved ones, in case we leave them suddenly.

Inside an hour, I had found the secret app, hidden away in a folder called ‘tools’, with the calculator and the pedometer and all that. It was called AirAse, something that sounded boring and technical. Instead, as another trip to Google told me, it was an app that automatically deleted all the data viewed on it, once it was clicked out of. There was no way to find what my husband had looked at. Gripping the chipped edge of the computer desk, I felt swayed by despair. How would I find this woman?

Then I had a thought. That last day, she had been in the car. That meant he must have picked her up somewhere – and there was a good chance he would have called or texted her, to arrange it. Maybe he hadn’t got round to deleting the phone history before the accident, if he was driving. I went through the list of numbers with trembling hands. What if she answered, and I found myself speaking to her, this woman? I would fake a wrong number, though I didn’t know if I might be overwhelmed by rage. I had to try at least.

The first thing I saw was that he’d made a lot of calls that day – unusual. Like most people, he mainly used his phone for texting or the internet. One of the mobile numbers went dead – abandoned. Another opened with a blare of noise, like it was a warehouse or market stall or something, then went dead when I said hello. The last – made just an hour before the accident – went to voicemail. Hello, this is Suzi Matthews. We’ve no reception at the new place, so please leave a message!

Suzi. Suzi Matthews. An upbeat, husky voice, with a tinge of Midland vowels. This was her, I was sure. The woman who had left you to die.