There must be more in this affair of Inglethorp's with Mrs. Raikes than we thought, to make him hold his tongue so persistently. 
He usually is a quick talker and leads the conversations.
mnli hypothesis: He usually is a quick talker and leads the conversations. premise: There must be more in this affair of Inglethorp's with Mrs. Raikes than we thought, to make him hold his tongue so persistently. 