I could think of a number of reasons why Waters should. Perhaps she saw the necklace as her means of escaping a life of servitude. Perhaps she had a lover who'd convinced her to steal the necklace for him. Perhaps she bore a secret hatred for her employer and had at last found a way to exact revenge.

I said none of these things to Lady Clifford.

"You see, Captain, I know quite well who stole my diamonds." Lady Clifford applied the tiny handkerchief once more. "It was that viper I nursed at my bosom. She took them."

I knew from gossip which viper she meant. Annabelle Dale, a gently born widow, had once been Lady Clifford's companion and dearest friend. Now the woman was Earl Clifford's mistress. Mrs. Dale still lived in the Clifford home and, from all accounts, continued to refer to Lady Clifford as her "adored Marguerite."

But all of London knew that Lord Clifford spent nights in Mrs. Dale's bed. They formed a curious menage, with Mrs. Dale professing fierce attachment to her old friend Lady Clifford, and Lord Clifford paying duty to both mistress and wife.

"Do you have evidence that Mrs. Dale took it?" I asked.

"The Runner asked just the same. He could produce no evidence that Waters stole the necklace, yet he arrested her."

The arresting Runner had been my former sergeant, Milton Pomeroy, who had returned from Waterloo and managed to work his way into the elite body of investigators who answered to the Bow Street magistrate.

Pomeroy was far more interested in arresting a culprit than in slow investigation. He was reasonably careful, because he'd not reap a reward for the arrest if he obtained no conviction. But getting someone to trial could be enough. Juries tended to believe that the person in the dock was guilty, and a maid stealing from an employer would make the gentlemen of the jury righteously angry.