Boris's words, "I believe you would sell us!" and her answer, "The price would have to be enormous," given lightly, it was true, yet might not there be a substratum of truth in it? 
Boris thought they were going to be sold as slaves.
mnli hypothesis: Boris thought they were going to be sold as slaves. premise: Boris's words, "I believe you would sell us!" and her answer, "The price would have to be enormous," given lightly, it was true, yet might not there be a substratum of truth in it? 