Under the glare of the Branch men he referred to his notes. ‘Smart address. Upper-class rooming house. It took us a while to get past the major domo and the maid to the owner. A Mrs Throckmorton eventually deigned to give me her card.’ Hopkirk leafed through his notes again and unclipped a small, white, gilt-edged card. He passed it over the table.

Bacchus took it eagerly. ‘No idea this place existed,’ he said. ‘Is it kosher?’ He scanned the card again.

Mrs Adela Throckmorton.

Choice accommodation for single ladies visiting the city.

A home from home in Mayfair.

Congenial chaperonage arranged.

‘Chaperonage?’ he questioned.

‘They run a service escorting young ladies to concerts and exhibitions, the theatre, even shopping trips. They do pick-ups and deliveries to railway stations. You know — a sort of “Universal Aunts”.’

‘Mmm … no suggestion of an Uncles Unlimited facility, I suppose?’ Bacchus asked.

‘You’re not the only one with a dirty mind, Bacchus,’ said Hopkirk. ‘Thought did occur to Inspector Chappel here. This is Park Lane we’re talking about, within a stride or two of Pinks.’