‘I hope you’re not thinking of giving up.’ Floriano read my thoughts as we drove along Ipanema Beach.

‘Of course not. But I really don’t know where I should go from here.’

‘Patience is the key, Maia. We will simply have to wait and see if Yara responds to your note. And of course we must continue to check on the Casa to see whether they reappear. Normally under these circumstances there’s no great mystery, just a perfectly rational reason. So, in the meantime, I suggest we think of what the explanation could be.’

‘They’ve gone away to visit relatives?’ I voiced my earlier thought.

‘A possibility, but given how frail the old woman seemed, I doubt she was up to long journeys. Or any pleasant small talk once she’d arrived.’

‘Then maybe they’ve left because they’re scared we’ll return?’

‘Again, a possibility, but unlikely. Senhora Carvalho has lived in that house for all of her life, and even though she didn’t seem keen to discuss your possible relationship to her, we were hardly wielding guns and knives,’ he mused as he drove. ‘Personally, I think there’s only one reason that neither mistress nor servant are at home at present.’

‘And what’s that?’

‘That Senhora Carvalho has been taken ill, and has had to be moved to a hospital. So, I think I shall call the local ones and see if my dear “great-aunt” has been admitted to any of them in the past twenty-four hours.’

I looked at Floriano in admiration. ‘You could well be right.’

‘We’ll go back to my apartment and I’ll look up the local hospital numbers, then call around them,’ he said, taking a right turn off the Avenida Vieira Souto instead of continuing along the seafront to my hotel.

‘Please, Floriano, I don’t want to bother you. I can do it on my laptop.’

‘Maia, will you please shut up. The letters I read this morning are some of the most interesting I’ve ever laid eyes on as an historian. There’s also something else in them that I haven’t told you about yet, which makes them still more fascinating. And perhaps even solves a long-standing mystery about the Cristo. So please believe that we are helping each other. I’m warning you, though, my home isn’t exactly the Copacabana Palace,’ he cautioned as we continued to head away from Ipanema Beach.

Shortly afterwards, Floriano made a sharp right turn and pulled his car up on a small concrete strip in front of a crumbling apartment building. It was probably only five or ten minutes’ walk from the hotel, yet it felt like a different world.

‘So,’ he said, as we got out of the car and climbed up the steps to the front door. ‘Welcome to chez moi. There’s no lift, I’m afraid.’ He opened the front door and began to bound up the narrow staircase two steps at a time.

I followed him up and up, and up again, until we arrived on a small landing and unlocked the door.