There were three keys on the ring and Prue tried them, one at a time, in the front door. At the turn of key number three it swung open and she walked into a large square hall. A dim light came on automatically, highlighting the dust as she took off her woolly hat and stood on a strip of dirty coir matting to stamp her feet and shake the rain from her shoulders.

She closed the heavy door behind her and absorbed the sudden silence. Well, she was here. Wet and weary, with her arms feeling like they were about to pop out of their sockets after lugging her case all the way from the station, but here. So now what? The hallway was deserted and she stood for a moment, taking in her new surroundings. The wallpaper was ancient, the stippled kind, with a dull cream-coloured paint daubed over the top and the scuffed skirting boards finished in a pale shade of green.

Despite a collection of numbered boxes set out in three tiers to hold the post for each individual flat, there was also a teetering pile of what must be unwanted junk mail strewn across the front of the long rectangular table, giving the impression that it was down to the residents to pick everything up off the mat and sort it, and that the leftover stuff with no obvious recipient had probably been there for a long time and might never be read at all. It was a strange and not very private system, very open to theft, and one that would have worried her a lot had she been expecting any post of her own. Still, she noted that the box marked 9 was empty, although policing its contents, or lack of, was really not down to her. A few curry house and pizza takeaway leaflets were pinned haphazardly to a corkboard up above, and a battered pink baby buggy lay pushed up against the wall.

Flats 1 to 3, each one identified by a large brass number on its door, led off the hall, one to each side and one at the back. Ahead of her was a steep narrow staircase with thin grey carpet fraying at the edges which she assumed must lead up to the others. With three floors and three flats on each, it didn’t take a lot of calculation to work out that flat 9 was likely to be on the top floor, and there was no sign of a lift.

Prue sighed. As she started up the stairs, bumping her case step by step behind her, she asked herself why she had brought quite so much stuff with her, and why she was here at all, whether her rather hasty retreat from Norfolk and the distance she was putting between herself and Joseph Barton would make any real difference to the way she felt. Or, perhaps even more importantly, to the way he felt.

It was the beginning of March, not the ideal time of year to take a holiday, but waiting for warmer weather was not an option. She had needed to escape now – right now – before anyone realised what she was doing and tried to stop her, and the house swap site she had stumbled across on the internet had provided what had seemed like the perfect solution. Besides, she was hopeful that London would have plenty of attractions on offer whatever the weather. Art galleries, department stores, museums, and she was determined to take a look at Buckingham Palace while she was here and watch the changing of the guard, just like Christopher Robin and Alice. Enough to do, surely, to distract her from the aching feeling, part bewilderment, part shame, that had overwhelmed her and that she knew was going to be so hard to shake off.