What's the twist, or must I say hook?!

Rutger Oosterhoff There are twists at every turn in this. It's a whodunnit thriller with lots of misdirections. And the fact that our main guy is constantly hallucinating that his dead partner is there with him.

... So the murderer could be anyone except the police detective?

Rutger Oosterhoff Best way I can answer that without giving things away is that it could basically be anyone except our lead. There are times along the way when other characters have traits that make the audience think it's them.

Sounds thrilling, Travis Seppala!

Almost solid logline. I suggest changing "former detective" to "_______ (the main flaw that he has to overcome in the script or an adjective that describes his personality) detective." You put "retirement," so we know he's a former detective.

And I think the logline needs something to make it pop more. Based on your logline and your comments, something like: Haunted by hallucinations of his murdered partner, a _______ detective comes out of retirement when her killer strikes again... a killer who could be anyone."

Maurice Vaughan I mean... I would argue that the hallucinations ARE what he has to overcome?

Ok, maybe just remove "former," @Travis Seppala. Or maybe use an adjective that describes his personality.