- Are you going to the, um, leaving thing tonight for Cathy? - Yeah! I wasn’t going, but I am now, because you’re going to be there, and, suddenly, it seems like the best idea ever. No, I’m not. - Change your mind! I’m going. I’ll give you a lift. Why not? - Um, actually, now that you mention it, seems like the best plan ever. Thank you. No, I’ve got some reading.
Focus on the dream, focus on the details, picture them, feel them. The TARDIS will track on your subconscious and extract the relevant information. It should be able to home in on the moment in your timeline when you first had that dream.