“He was a known gambler and blackmailer, ma’am. I suspect somebody took the opportunity to get out of a debt to him, but I don’t know how I could find out who that was. I have no idea about gambling dens.”

“Of course you haven’t. But it must also have been somebody who knew your family—on equal terms, so to speak. You don’t risk drowning somebody in a peer’s bathtub if you are a laborer or a bank clerk.”

I nodded. “One of our set, then.”

“It must have been somebody who had at least passable knowledge of the workings of Rannoch House. Someone who knew your brother reasonably well, I’d say. Do you know which of his friends has visited the house on a regular basis?”

“I’m afraid I have no idea, ma’am. I’ve rarely been in London apart from my season, and have hardly stayed at Rannoch House since my father died. But from what I know of my brother, he doesn’t come to London unless he has to. He much prefers pottering around his estate.”

“As did his grandfather,” the queen said. “The old queen had to practically issue a royal command to make him bring his wife to court to visit her mother. So you don’t know which of your brother’s friends is currently in London?”

“I’m afraid I don’t even know who his friends are. If he meets them it would be at his club.”

“Perhaps you could make discreet inquiries at his club, then. Brooks, isn’t it?”

“Easier said than done, ma’am. Have you ever tried to persuade a gentlemen’s club to tell you who is currently in residence?”

“I can’t say I ever had to, not having the wandering kind of husband, but I’m sure my predecessor, Queen Alexandra, had to do so on a regular basis. But this may be one area in which the palace can help. I will ask the king to have his private secretary visit Brooks on our behalf. I believe he’s a member. I hardly think they will refuse him the information, and if they do, he can always take a look at the membership book, can’t he?”

“That’s a splendid idea, ma’am.”

“And in the meantime, keep watch. The murderer may want to know how the investigation is going. He may be enjoying your brother’s current humiliation. They say murderers are vain fellows.”

“I’ll do my best, ma’am.”

She nodded. “Well, let’s see what Sir Julian can unearth for us, shall we? We should know something by the time you return from Sussex on Monday.”

Sussex? I racked my brains to think of any royal relatives who lived in that county. Her Majesty frowned. “Don’t tell me you have forgotten about the small assignment I gave you—the house party at Lady Mountjoy’s.”