If time travel was beyond the understanding of scientists – including the mega brains of men like Stephen Hawkins – there was little point in Lou with a GCSE in physics trying to work out how it was possible. The only question she could hope to answer was why. Why had she, of all people, been allowed to travel back in time? Whatever force had taken her back must have had a purpose for her. She couldn’t repay that force by sloping home to clear away a week’s worth of takeaway cartons and junk mail.

Lou snapped off the light on her phone. She left the churchyard and headed quickly back to town, navigating the afternoon rush hour traffic. After calling into a newsagent to buy a notebook and pencil, she stopped at another relic from the nineteen-sixties town-planning boom.

The closest she had come to this building since leaving for Sheffield was walking along the opposite side of the road on her way to work. A few months back she’d toyed with joining the book group that met here, but in the end, she hadn’t bothered. Not because she thought herself above spending every other Tuesday evening in the company of a group of locals, dissecting the latest Zadie Smith or Kate Atkinson, over a cup of weak tea and a chocolate digestive. If only the decision had been that thought-out and considered. It hadn’t really been a decision at all. It was simply that it had been easier to spend evenings in the pub or slumped in front of the telly rather than doing something that required thought or effort.

Lou’s ghostly reflection stared back from the library window. Growing up, she had spent entire days here, her nose stuck in a book, studying, keeping clear of her noisy brothers. Now she had abandoned this place. Just as she had tossed that little girl’s dream of becoming a teacher aside, like a bag of half-eaten cold chips.

Christ, she was beginning to sound like a stuck record. She had always criticised anybody who moaned about their lives and did nothing about it. And here she was; one of those people. Well, no more. For the first time in years, she would do something.

The vent above the door blew warm air on to Lou’s hair and the musk of paper wrapped around her like an old comfort blanket. The librarian stopped arranging books on a trolley and looked up. Lou prepared herself for a sharp look, warning against any transgression of the strict policy of silence. When Mrs Rogers simply peered over the rim of her glasses, an inkling of recognition resulting in the briefest of smiles, Lou’s muscles softened like dough in the hands of an experienced pastry cook. The years fell away. She had been granted admission to the world where a library card was the passport to realms beyond her grim hometown.

Lou strode to the bank of computers and took a seat. A man and two old ladies already seated there took no notice when she shrugged off her parka and draped it over the back of the chair. Flipping open the notepad, she placed it on the desk, its perfect blankness like a field of virgin snow. She placed her fingers on the keyboard and began to type, calling up the archive of the old local newspaper, The Courier. On the search page, she punched in a date range between 1915 and 1930 and entered “Caxton” as a key word. She had to begin with a known fact; that Charlotte had married George.