I lifted my head to the grand ceiling above us, scanning my gaze across the carved cornices, the shimmering chandelier, and hundreds of years of Armstrong life and love.

‘We keep looking.’

Once we’d finished clearing up, and rewarded the children’s hard work with the promised hot dogs, they settled in front of a Christmas film while Jed, Mia, and I resumed the search. We had a couple of hours before Jed and I were setting off to the hospital, so we decided to focus on the four large boxes of memorabilia that Nana Joy often opened up when we were younger, which were in Nana Joy’s bedroom.

‘Remind me what we’re looking for?’ Mia asked.

‘Anything relating to people who Nana Joy might have confided in,’ Jed said. ‘Or who might have discovered her secret another way. A personal assistant, best friend, her doctor. Or, even better, any reference to the list of potential names from A Murder in Paris, on that Post-it. If we put anything that looks promising in a separate pile, we can go through them later when we’ve got more time.’

It was a small pile. By the time we had to leave we’d worked through two of the boxes. After a brief debate we put those away and carried the remaining two up to my attic room, so we could go through them another time without arousing suspicions from Mum or Dad.

We’d found the name of a housekeeper and personal assistant in an interview about how she managed as a successful, working woman. Joy had declared them to be, ‘Absolute pearls! They know me better than I know myself, and I couldn’t manage without them.’

A couple of photographs showed her on the arm of the murderer from A Murder in Paris, but they were all in the year or two after Dad had been born, and it seemed unlikely that she’d have remained so close to the father of her child while keeping his identity hidden.

There were a few other names mentioned that we felt it worth following up on, but it was all very tenuous and vague, and we couldn’t help drawing the same conclusion.

‘Maybe we should just ask her?’ Mia said, as we tidied everything back into the boxes. ‘Being so ill might make her reconsider keeping such a big secret.’

‘Maybe, but it seems wrong to bring it up now, considering it’s such a forbidden topic,’ Jed replied.

‘She knows that Charis House is in trouble. What if we came around to it that way?’ I suggested. ‘We could mention how it’s a shame none of the Armstrongs can help, and subtly wonder whether there might be anyone on Dad’s side of the family. If she starts getting upset at any point, we can change the subject.’