‘Not exactly. Bowie had something called anisocoria, which is when a person’s pupils are two different sizes. Heterochromia affects the iris, not the pupil. In Kitty’s case, it meant her left eye was blue, her right eye was green.’

‘I’m guessing the woman you saw had the same condition?’

‘She did, but it wasn’t just that. I’m not stupid. Six people in every thousand have heterochromia. It was more than the eyes. It was everything about her. Not her hair, which she’d dyed. Kitty’s hair was brown and she’d always worn it long. This woman’s hair was blond – Marilyn blond – and cropped short. But her face, the way she walked. I forgot to tell you that. Kitty had a slight limp, and so did this woman.’

Dee refrained from pointing out that this, too, was hardly proof the woman was Emer’s dead sister. It was clear Emer had convinced herself Kitty was still alive. Until Dee could prove otherwise, Emer wasn’t going to change her mind.

Fifty minutes later – because in London that’s how long it took to travel four miles by car during rush hour – Dee and Emer were climbing out of the black cab onto a quiet, cobbled street lined with leafy trees and yellow-brick converted warehouses. The Town of Ramsgate was situated at the end of a particularly impressive warehouse conversion that, Dee was pretty sure, had once counted Cher as one of its celebrity residents.

‘Okay,’ Dee said. ‘So you’re going to stay out here while I go inside and ask if anyone knows a woman with bleached blond hair and two different coloured eyes?’

‘One green, one blue.’

‘Got it.’

The pub door was closed, but when Dee peered through the window, she was able to see the people inside. Behind the bar, a tall, striking, eighties-era Annie Lennox lookalike was pulling a pint of Guinness.

‘Is that her?’ she asked, stepping back from the window to make room for Emer. ‘Short blond hair, working behind the bar.’

Emer looked through the window for a long time, without speaking.

‘Well?’ Dee said. ‘Is it her or not?’

‘Yes.’

‘You don’t sound too certain.’

‘It’s her. One hundred per cent.’

She certainly didn’t sound 100 per cent convinced, Dee thought, as she pushed open the door and walked inside. The door swung shut behind her and she waited for her eyes to adjust after the bright sunshine. The pub was a long, narrow room with the bar running down one side. Original stained glass panels on wooden partitions separated the space into cosy snugs. It had been updated since Dee’s last visit, sometime around the millennium, but it was familiar enough to trigger a host of memories.