Since Berlin and Red both have the same picture of the same woman (who we now know is Berlin’s daughter), what If Red was the one his daughter fell In love with when she was young? She was Red’s wife and she and Red had a daughter, who is Lizzie, making Berlin Lizzie’s grandfather. Berlin has been led to believe his daughter is dead, which is why he is so intent on going after Red because he either blames him for her being taken away, or he thinks Red is the one who killed her. Since the stewmaker had Berlin’s daughter’s picture as a trophy (the one that Red took), we know he killed her and was the one who sent her back in pieces. Red knew after his wife (Berlin’s daughter) was murdered that Lizzie would be in danger and didn’t want Berlin to know they had a daughter so he passed her off to Sam to keep her safe (that’s why he says if she knew who her father was, she would be in danger (bc Red is being hunted and doesn’t want her to know she’s his daughter in order to protect her)). Like Berlin said in the hospital, “No one knows Berlin’s real name”, including Red, and Berlin is just an alias so Red doesn’t figure out who he is.