Haven – "Everything is mixed up, truth and falsehood" [Campaign 3 – Mission 2]

Please help, I can't figure out how to complete the mission and capture the first Castle. I think I need to complete Kilburn's quest list first. If that's the case, please tell me how to do it. Also, how do I complete this mission? I'm panicking; I don't know what to do. I've been racking my brain over this mission for two days now!