Isaac was the husband of Tamara, he was an associate of Bobby Singer and the father of a young daughter who died.
Background[]
Issac and Tamara meets Bobby and the Winchester brothers
Isaac married Tamara around 1999 and they eventually had a daughter which they raised in Lincoln, Nebraska. After their daughter was killed by an unknown monster, the two began hunting and eventually came to know Bobby.
When the Devil's Gate was opened in 2007, the two went to investigate a town where the Seven Deadly Sins had been operating and came across a house where three people had died from starvation and dehydration. Outside, Isaac and his wife met Dean and eventually Bobby whom they recognized, he later refused to work with Sam and Dean under belief that they had been the ones to let the demons out.
Later that night, he and Tamara made their way to a bar known to be visited by Walter Rosen who had been possessed by the sin Envy though it was a trap and the two had been set up by the demons inside. Gluttony then used his ability to order Isaac to drink bleach in front of his wife to which he did and he died within seconds from the internal damage inflicted upon him.
His body was then possessed and he attempted to trick Tamara into letting him inside the house where she, Sam, Dean and Bobby were though Tamara, knowing her husband was dead, stabbed him and the demon inside was exorcised by Bobby.
After the rest of the sins were killed, Tamara gave Isaac a hunter's funeral.