L ike all great love stories, this one begins with sweat-patches. It was July 2018, and London was in the grip of the kind of heatwave that melts tarmac. At 7.

21pm, Emily Lewis stumbled off the train in a state of panic. She was meant to be attending a Guardian Blind date in exactly nine minutes, but her T-shirt was soaked with sweat. Spotting a Gap store across the road, Emily dashed in and bought a new top almost at random, hiding her wet shirt at the bottom of her rucksack.

With three minutes to go, she power-walked to the restaurant, but at the door she faced another hurdle – the hostess had never heard of the Guardian, let alone Blind date. Sweating through her new top, and almost ready to give up, Emily felt a tap on her shoulder. A woman with dark hair was smiling at her, looking cool and unruffled.

“I’m Sophie,” she said. “And I think you’re my date.” The rest of the evening ran more smoothly.

Once Emily was actually sitting down, with the full force of the restaurant air conditioning washing over her, she began to have that very specific good first-date feeling – the kind you experience perhaps once or twice in a lifetime. Sophie Swain was beautiful, and curious, and talking to her felt almost preternaturally easy. Sophie, for her part, thought that Emily looked remarkably composed, for a woman who had just sprinted through central London in 34C heat.

Emily made her laugh, and she had an amazing quiff. Just before midnight, they walked to the station .