Even if Hunt Rennie did not appear bodily in the Four Jacks tonight, Drew could pick up information about his father merely by keeping open ears.
Hunt Rennie's father was the same age as Drew.  
mnli hypothesis: Hunt Rennie's father was the same age as Drew.   premise: Even if Hunt Rennie did not appear bodily in the Four Jacks tonight, Drew could pick up information about his father merely by keeping open ears.