At the risk of being unfashionably enthusiastic, Scotophobia is already my single favourite 5e/6e plot book. There is a lot happening, and it is so easy to bring it into my home games. I'm planning on running Third Parallel first (I was already going to start it soon, but now it is also a good lead into the events in Scotophobia), but I'm already just about salivating at how I'm going to kick things off, some of the big names that are going to show up in our games (everywhere from a news brief to actually talking to PCs), some of the high stakes events that should provide a ton of motivation beyond just survival, profit, and the power of friendship.
It doesn't hurt that it aligns with a bunch of themes that were already in my home games, but even without that I think it is just such a useable book as a GM.