‘The acid? It’s there. It was filled up on Friday.’

‘Bailey must have missed it. Don’t worry—we saw the stains and felt we ought to account for them. What about these rooms?’

‘All the students’ rooms are up there,’ said Troy, and pointed to the upper landing on the right. ‘The bathrooms, and mine, are on the other side. Through here’—she pointed to a door on the halflanding—‘are the servant’s quarters, the back stairs and a little stair up to the attic-room where—where Sonia slept.’

Alleyn saw that there were lights under two of the doors on the student’s landing.

‘Fox and Bailey are up there,’ he said. ‘If you don’t mind—’

‘You’d better do my room,’ said Troy. ‘Here it is.’

They went into the second room on the left-hand landing. It was a large room, very spacious and well-proportioned. The walls, the carpet, and the narrow bed, were white. He saw only one picture and very few ornaments, but on the mantelpiece sparkled a little glass Christmas tree with fabulous glass flowers growing on it. Troy struck a match and lit the fire.

‘I’ll leave you to your job,’ she said.

Alleyn did not answer.

‘Is there anything else?’ asked Troy.

‘Only that I should like to say that if it was possible for me to make an exception—’

‘Why should you make any exceptions?’ interrupted Troy. ‘There is no conceivable reason for such a suggestion.’

‘If you will simply think of me as a ship’s steward or—or some other sexless official—’

‘How else should I think of you, Mr Alleyn? I can assure you there is no need for these scruples—if they are scruples.’

‘They were attempts at an apology. I shall make a third and ask you to forgive me for my impertinence. I shan’t keep you long.’

Troy turned at the door.

‘I didn’t meant to be beastly,’ she said.

‘Nor were you. I see now that I made an insufferable assumption.’

‘—but you can hardly expect me to be genial when you are about to hunt through my under-garments for incriminating letters. The very fact that you suspect—’

Alleyn strode to the door and looked down at her. ‘You little fool,’ he said, ‘haven’t you the common-or-garden gumption to see that I no more suspect you than the girl in the moon?’

Troy stared at him as if he had taken leave of his senses. She opened her mouth to speak, said nothing, turned on her heel and left the room.

‘Blast!’ said Alleyn. ‘Oh, blast and hell and bloody stink!’