"I thought so," said the detective, calmly.
"Why did you think so?" asked Monteith, impatiently.
"In the first place," remarked Roper, complacently, "I had the honour of coming home in the same boat with Mrs. Verschoyle; secondly, I made her acquaintance as Signer Clement, and she liked me very much. I had frequent conversations with her, and told her I was a friend of Vassalla's."
"But you don't know him," said Ronald.
"All's fair in love, war, and--detective work," observed Roper, quietly; "I told Mrs. Verschoyle,--who I knew, from Mrs. Dexter's diary, was in love with Vassalla,--that the Marchese wanted to marry Carmela Cotoner, her sister."
"That's true enough," said Foster; "he's engaged to her now," whereat Ronald winced.
"The result was I aroused her jealousy, and she swore that she would prevent the marriage."
"But how?" from Ronald, eagerly, fain to cling like a drowning man to a straw.
"That's what I could not find out," said Roper, thoughtfully; "she said she could stop the marriage, and Vassalla would have to obey her. Now, what logical inference do you draw from this?"
"That Vassalla committed the murder!" said Ronald, hastily.