"What? Where?" they all cried in one breath.
"Yes, Richmond Hill! It was the name of a big mansion and estate outside of the city, and was a very famous place in its time."
"But how did you know it had anything to do with Alison?" they demanded incredulously.
"Well, just about twenty things pointed to it without a doubt. I'll tell you all about it. In the first place, I read that this mansion was built in 1760 by the paymaster-general of the British army, and his name was—Abraham Mortier!"
She stopped significantly, but no one seemed to catch her meaning till Margaret suddenly cried:
"Madame M.!"
"Precisely!" said Corinne. "I wondered if you'd catch it. 'Madame M.' must have been Madame Mortier, his wife, of course!"
"But Alison didn't say anything about Abraham Mortier," objected Bess.
"That's just it,—she didn't, because Madame Mortier was then a widow. Her husband died quite suddenly, just at the outbreak of the war. So that's accounted for. And don't you remember that Alison said Madame M. allowed the steward to transact all the business of the household. She wouldn't be doing that if her husband were alive! Well, except for that, I couldn't find out another thing about the Mortiers. History doesn't mention them again. But it tells a lot about other things we're interested in. To begin with, after the siege of Boston, Washington came to New York, and was there several months. Now then, while he was in the city, he made his headquarters at—Richmond Hill! What does that suggest to you?"