(AMC) Does anyone remember the situation behind Zach proposing to Kendall?

All I remember was that she was in a relationship with his son, who died sometime later. Father and son wasn't getting along, and for some reason he didn't want her with him. So he made a business proposition to Kendall to this day I don't understand how she could turn her back on the man she supposedly loved to marry his father. I also couldn't understand how Zach could do that to his son if he claimed that he wanted to make peace with him. It's very galling. I call it ill-gotten gains. Everything else is fuzzy but the previous comments I remember clearly. Can anyone else fill in the blanks? I'm sure I will remember the rest as I am informed.