Almost at once another door opened directly across the hall, and a hand appeared and, somewhat surprisingly, signalled to him. The hand belonged to a young woman of bookish appearance, her russet hair severely restrained and a pair of rather ugly wire spectacles perched on her nose behind which two very intense eyes stared at him. She wore a faded slate-grey silk morning dress that had seen the end of too many darning needles but she seemed unconscious of the fact, or indifferent. Alasdair went to her and at her behest stepped inside her doorway. She looked to the left and right and then behind her, as though there was another in the apartment whom she did not wish to overhear her.

‘I am Miss Tiptree,’ she hissed, as though that explained all.

‘Good day to you, madam—’

‘Hush—please! Mama is asleep but she sleeps lightly. You are enquiring about Miss Trent? I thought so. You have not heard, then, what happened a few days ago?’ And not awaiting his reply: ‘It was on Saturday, very early in the morning, that we heard a commotion. For that is the only way I can describe it. Mama and I were not yet breakfasted when we heard the noise—or noises, really …’

‘Please, Miss Tiptree, what happened?’

‘A police constable—or, rather, two police constables!—came to the house, came specifically to Miss Trent’s apartment. They could not get in, for she did not answer, she was already gone out, or so we believed, but we let them in—’

‘Let them in? How?’

‘I have a spare key. Miss Trent entrusted me with it. For emergencies. This was the emergency—though I confess when one is handed a spare key for an emergency one does not really anticipate there will be any such emergency, does one?’

‘No indeed. But Miss Trent?’

‘I was made to wait outside—indeed, I was urged by the constable to return to my rooms, but I confess I did not. I lingered, as who would not?’

Miss Tiptree paused here to blink rapidly a number of times.