“It’s from another man,” I said. “What was Bobo doing with it?”

I picked up one of the photographs. It was of a group of men in bathing costumes, standing with arms draped around each other’s shoulders. I thought some of them looked familiar. It was a small snapshot and I peered harder. “That one looks quite like Major Beauchamp-Chough,” I said. “Only younger and minus the mustache.”

“Probably a younger brother,” Darcy said. “Although most army types tend to look the same. Eton and Sandhurst, you know.” He peered at the photograph. “I don’t know why she’d want snapshots of men on a beach. But look at this.” He held out a picture of a woman standing with a pretty little girl of six or seven by a country cottage. On the back of the snapshot someone had written, She looks just like you, Toby.

“Toby?” I asked. “As in Sir Toby Blenchley? But that’s not his wife?”

“Definitely not,” he said. “I get the feeling we know now how Bobo made her money. I thought it might be selling drugs, but look at all this. Incriminating evidence. I’d bet the farm that Bobo was a blackmailer.”

“Golly,” I said. “There are a lot of items here. So any one of these people would have wanted her dead.”

“I must take this lot to Sir Jeremy,” he said. “I think I’d be playing with fire if I started probing too closely into Sir Toby’s life without proper authority.”

“But she was reputed to be his mistress,” I said. “How could she be blackmailing him?”

“That may be how she worked. She became friendly with powerful men. They gave away too many secrets in the heat of passion and she threatened to expose them. Men with too much to lose.”

“Like Sir Toby,” I said. “The least we can do is to ascertain his movements on the evening Bobo was killed.”

Darcy shook his head. “I already told you that a man like Sir Toby wouldn’t do his own dirty work. He’d have hired someone.”

“Could he risk hiring someone?”

“I expect he has a loyal underling who has done unpleasant jobs before and is well paid for his silence,” Darcy said. “It’s strange how powerful men think they are untouchable.”

“I wonder why he didn’t have someone try to break in here to retrieve the evidence from the safe,” I said, staring down at that snapshot.

“She probably made him think the evidence was in a bank vault or somewhere equally untouchable. In that bank in Switzerland, maybe.”

I leafed through other photographs and letters. I came across a picture of Bobo in a bathing suit, sitting on a yacht with Prince George. He had his arm around her shoulder and they were both holding cocktail glasses. “Surely she couldn’t have tried to blackmail him?” I asked.