What is the background story of Jimmy being friends with his daughter’s biological father? I watched S1 and S2 ages ago and faded out in S3, missed S4 and caught a bit of S5 which looks interesting. I lost track of the details. This show is hard to find in the US. It randomly is aired on public tv channels.
It's entirely weird, IMHO. Either they haven't said or I can't remember, but Duncan must have gotten divorced from the mother when Cassie was really young. It makes zero sense that Cassie would have continued to live with her step-dad Jimmy after her mother died. Duncan appears to be more affluent than Jimmy is (bigger house, some kind of real estate business), although he has remarried and maybe with a change of custody his wife did not want his daughter to move back in.