'Did you? Did you know it?' Sidney was asking them impatiently.

'Know what?' Lady Helen said.

'That Deborah's involved with Tommy. Tommy Lynley! Mummy's cook told me, believe it or not. From what she said, Cotter's quite up in arms about it. Honestly, Simon, you must talk some sense into Cotter. For that matter, talk some sense into Tommy. I think it's completely unfair of him to choose Deb over me.' She resumed her stool. 'That reminds me. I've got to tell you about Peter.'

Lady Helen felt a margin of relief at this welcome change of subject. 'Peter?' she said helpfully.

'Imagine this.' Sidney used her hands to dramatize the scene. 'Peter Lynley and a lady of the night — dressed all in black with flowing black hair like a tourist from Transylvania — caught in flagrante delicto in an alley in Soho!'

'Tommy's brother Peter?' Lady Helen clarified, knowing Sidney's proclivity for overlooking pertinent details. 'That can't be right. He's in Oxford for the summer, isn't he?'

'He looked involved in things far more interesting than his studies. History and literature and art be damned.'

'What are you talking about, Sidney?' St James asked as she hopped off the stool and began to prowl around the lab like a puppy.

She switched on Lady Helen's microscope and had a look through it. 'Crikey! What is this?'

'Blood,' Lady Helen said. 'And Peter Lynley?'

Sidney adjusted the focus. 'It was… let me see. Friday night. Yes, that's right because I'd a grim little drinks-party to attend in the West End on Friday and that was the night I saw Peter. On the ground in an alley. Scuffling with a prostitute! Wouldn't Tommy be pleased if he heard about that?'

'Tommy's not been happy with Peter all year,' Lady Helen said.