Location, Location, Location
So the first issue I had was finding a location - finding an actor wasn't hard as they didn't need to speak, just scroll through google images while at a desk.
I imagined the actor of the piece as a journalist type, a young professional of some sort - so I needed a desk where my actor (Cai) could sit and look focused. I also needed a space where I could control the lighting enough to make it seem like a different time of day - I wanted it to seem like Cai was reading a transcript of what the speaker says, and doing research on what he hears, and ends up working into the night. We spent ages looking around the school for an room we could use, but I kept finding that areas with good lighting weren't open enough for me to film in various angles, or it wasn't quiet enough to get anything done.
In the end, Mr Brodie let me use his office, which was actually perfect - he has blinds, as well as one of those sunlamps with two hinges on it so I could change which angle the light came in from. I had to take down some of his posters, as they were teacher related and I didn't want to mess up the background with something that didn't make sense with the narrative.
Angles
After I'd done my first round of filming, I showed Mr Brodie what I had so far and we agreed that the shots I had were kind of basic - all mid or close up pans from eye height. So I waited until the next time Cai came in wearing the jacket/hoodie combo he had on, and I took some more interesting shots - some from over the shoulder, some from very low to get a good shot of Cai's "This is interesting and I'm concentrating" face. The hardest shot was the one from above, for which I had one foot on a chair and the other just on the desk, and I had to spend the whole time making sure I: A) didn't fall off, and B) kept my foot out of the shot.
Audio
So, in hindsight, this was a really obvious one to fix, and I don't see why it didn't occur to me sooner.
I couldn't get the speech to overlap in tone with the tune I wanted to go underneath - to go from mild, then something like fascination, then to something vaguely sinister. My speech wasn't long enough to match with the song, and I couldn't speed the song up without it sounding silly - I spent about a fortnight agonising over how to fix it, thinking of finding different songs that worked better, begging a musically inclined friend to play what I wanted on the piano.
It wasn't until I was complaining about this to someone that they suggested I cut the track and use the relevant sections.