“You have police witnesses to the housekeeper’s confession?” he asked.
“Oh, yes, and several witnesses not of the police,” Norton answered. “Meyerson was present, and a man named Carvello. But let me go on. We found the key to the apartment in Miss Ballau’s purse the night of the murder. I looked for it myself and, on finding it, left it there. Miss Ballau, you will remember, testified she had lost the key some weeks before. Which explained why she had to ring the bell to get in.”
“These things are hardly sufficient for the arrest of Miss Ballau,” De Medici said quietly as the detective paused.
“I quite agree,” said Norton. “All this was evidence we had within two days of the murder. We didn’t act on it but continued our hunt for more. More was necessary and we waited till we got it.”
De Medici nodded.
“The motive, for instance,” smiled Norton. “Well, three days after the inquest, or two days, I think, Miss Ballau disappeared. We had been watching her closely but she managed to elude us. I put two of my best men in pursuit of her and I devoted my own time to finding out her history. I was able to discover through documents and inquiry that Florence Ballau was not Victor Ballau’s daughter but his stepdaughter. She was a year old when Ballau married her mother in London. As you see, this supplies the beginnings of a motive.”
Through De Medici’s mind passed a suddenly illuminated memory of Victor Ballau—the Ballau whose fingers had trembled as he poured the liqueur that night, whose eyes had turned away as he toasted the happiness of his prospective son-in-law. His heart grew heavy as the innuendo of the lieutenant unfolded its logical terminations before him.
“We would like to have your theory of the motive,” Dr. Lytton prompted the smiling detective. “Motives, of course, are always more interesting and more important than clews.”
“You were to be married,” Norton resumed, turning to De Medici. “And Ballau was jealous.”
“I see,” murmured De Medici. He sat staring at the man. Words suddenly danced excitedly in his head. “The thing is mad,” he cried. “You’ve let a preposterous notion run away with you....”