What a twist

Until ch18 I was 99% certain Isaac is Noah but now I don't think he is. I feel like Noah is the guy in the last pages of ch18 who took the tulips out from the trash. This would suggest Noah is indeed close and stalking Finn. Also Scott, the best detective, did not recognise him at all. If Isaac was truly Noah, Scott should have had at least some suspicion but he had none. Additionally, the police guy who looked into Noah's whereabouts said he is just working and minding his business, suggesting they are still keeping tabs on him. If he changed his name, or worked in the same company as Finn, for whom he has a restraining order, they surely would have known something.

I think Isaac is a different person who got close with Finn because she is his fastest ticket to Noah? Hence the "getting bored, so come out, Noah" part? I guess Isaac is connected to Noah somehow, either he was close to one of his victims and wants revenge or he is into psychopath stuff like Finn and wants a thrill. The first would explain his obsession with Finn. It would also explain how he remembers Scott's interview which happened years ago, suggesting that is the timefrme when the events that triggered his obsession started. Likely Noah killed the first two victims because he was looking for Finn, so when he found out they weren't her, he disposed of them. Isaac probably killed the last person to make it seem like a serial murder, hence, the sligthly different MO between the first two and last victims.

If Isaac is obsessed with Noah for any reason, this would also explain how he knows details of the first 2 murders so well. It would also explain why he thought it was "a waste to kill someone with only 2 slices, when you can do whatever you want with them". Like he had fun killing the third victim and then thought "Oh right, I must tie her and do the slashes."

Noah or not, the guy is dangerous af. I can't wait to see what will happen in the next chapters - if I was right or completely off track.