He waited in the stuffy room, the air thick with the scent of lemon drops and stewed tea. A tabby cat lay curled on a crocheted cushion. A single teacup and saucer sat next to an ancient electric tea kettle. When the gardienne hung up the phone, she fixed him with a gelid eye. ‘She’s willing to see you. But she doesn’t get many visitors these days, so mind you don’t tire her out.’ She waved her hand towards the hall. ‘The lift is at the back. Sixth floor.’ She crossed her arms and waited, as if expecting something more. Was she worried – or hoping – he was some kind of blackguard? A murderer, perhaps. Or a thief, at the very least. A little excitement to liven up her day. He bowed and wished her a bon après-midi.

The lift, no bigger than a coffin, rattled and jerked its way to the sixth floor. It opened with a metallic groan, and he stepped into the hallway. The faded maroon carpet smelled of dust. He knocked on the door to number 15 and waited. From the gardienne’s description he had the impression that Madame Joubert was a bed-ridden recluse, but the woman who opened the door had a gleam in her eyes and an impish smile.

‘Ah, Monsieur. Do come in.’ She led him into the salon and offered him a chair by the window. ‘I’d just put the kettle on for tea when Madame Dubonnet telephoned to say I had a gentleman caller. I hope she didn’t give you any trouble. Rather an ogress, that one.’ She winked. ‘Or would you prefer an aperitif? My son-in-law sent me a bottle of a delicious eau de vie last month. Peach, I believe. It might make for a little taste of summer on this dreadful day.’

Gessen said he would have whatever she was having. So she vanished into the kitchen and returned in a moment with a tea tray. He leapt up to help her, but she shook her head. ‘I’m not as decrepit as all that. It’s only when I sit too long that my bones freeze up.’

She set the tray on the table and settled into a brocade armchair. Her fine, candy floss hair was coiled in a loose chignon. A jewelled brooch in the shape of a chameleon glinted on the collar of her blouse.

‘Unusual, isn’t it?’ she said, catching his gaze. ‘My late husband had it made for me. When the children were grown, I returned to school to study biology, and later on I trained to be a docent in herpetology at the Parc Zoologique. I was keen to study for an advanced degree earlier in my life, but my father was dead set against his only daughter tramping about the countryside in search of snakes and salamanders.’

At the mention of snakes, Gessen nervously eyed the terrarium on the window ledge.