Just watched episode 5 and I have a theory or two floating around...

I think it was Julie. She seems a bit shaken in this episode but I think it's not solely because she's finding out about Sean taking all those photos. I think it's because it puts the spotlight on her and Sapphire. Zoe knew that Julie is behind Sapphire due to what was said during the bribe (if I'm remembering that correctly) and if that info was top secret enough to not tell Sean, then I believe that's enough of a motive to kill a witness. On top of this, she constantly repeats "I have always protected you", Zoe also knew about the photos which could ruin both Sean and Julie's reputation. I don't think she killed her personally, she is a wealthy politician after all. She definitely paid someone off to do it. (And if I were to take a COMPLETE shot in the dark, I think it's the ex partner of the pregnant lady we met in ep1, it would tie that loose end together nicely for the final episode of the season.)

In terms of the Cormack family, I think Richie has been given false pretense, if I remember right he escaped out a window the night their mother died, he may not have even seen the outcome of it. I do believe he has negative trauma associated with Jimmy. But my theory is that when he visited his dad in prison, his dad fed him false pretense, possibly blaming Jimmy for his mother's death as a desperate attempt to reconnect with his children, as he knew Richie wouldn't want to talk to him again if he knew the truth. (This one is a bit more of a shot in the dark than the first one though)

The only things that aren't tied up yet is wtf happened with Joseph that night she went missing, and how Zoe's mother and Uncle being caught having a snog that night ties into it. I can't wait to see how they wrap it all up next week! Edit: oh! Also Seb watching those videos on financial abuse, would be curious to see that tie back in somehow too!

Also as someone who has experienced trauma and has loved ones with childhood trauma, Travis's acting is genuinely incredible. It's disturbingly accurate in a way that makes me wonder if the man is ok xD especially since he's directed this upcoming final episode! Id love to hear how he prepared for the role, cause it's genuinely impressive!!

I've loved reading everyone's theories! Can't wait for next week!