Those caveats out of the way, here are some of my thoughts on the matter and how I set up the components of an investigation. I'll be diving into my notes for this one, so expect to see behind the curtain of GREAT SCREAMING HELL.
Avoiding the Mystery Box
You can throw all sorts of stuff into an investigative sandbox with no plan. That's cool, go wild. It helps to have a couple big picture movers-and-shakers out there but they can be buried under layers of other aspects.
In the aftermath of that initial burst it becomes necessary to do a bit of retroactive tissue connection. If X person did action A, whatever motivation they are revealed to have later on should be consistent with that action.
Something has to kick off the investigation. Whether the players are proper investigators or just folks caught up in things, the best way to kick off the investigation is something big, mysterious, and in-your face.
Example: The players are ambushed by a monster while transporting a strange cargo.
Seeds and Threads
The core of an investigation. Seeds are the clues found during play, and Threads are the things that connect or expand upon those seeds. Simple enough. To ease up on work for the referee's end of things, the inciting event should open the door (If the players are birds, dump a bucket of suet on them), and further sessions can focus, connect, refine, and tie in new stuff. It's okay to come up with answers after the fact - I actually really like the mind game of tying together disparate parts into a whole. It's also okay that the players don't get those answers handed to them.
Basically, when prepping for your next session, make a bullet list of your available seeds and see where they might connect and lead, which ones might interfere with the players, and how thread (especially ones involving factions) will act and react to changes in the world.
Example: The first session of GSH contains a truckload (har) of seed questions.
- Who is FRIEND? Why are they shipping the Box?
- Who is Scipio? Why did they want the Box?
- What was in the Box? Where did it come from?
- [Behind the Veil: The box contained a Navigator, and thus the only remaining functional warp interface in the system. It was presumed lost or destroyed during the aftermath of the Zaibatsu's departure. FRIEND was apparently trying to get it out of Colony Central.]
- What was and what was up with the Beast?
- What was up with the radio station?
For the second session the players ended up investigating the radio tower. (As a strike against myself, this was not under their investigative power but me guiding things as referee), and moved right on in the third to the abandoned Weather Station. This brought with it its own seeds.
- Dess Kartz' testimony
- He and his companions were attempting to recover the "Holy Interface" (IE, the cargo)
- The android cult of the Church of Skin
- Had its own Interface (the horrible thing in the garage)
- Under investigation by both the tecnavi ship-mother in orbit around the moon, and by a couple of mercenaries of the Legio Africanus (Scipio's boys)
- [Behind the Veil: I never decided if the Legio Africanus guys were killed by the tecnavi agent or by Lady Badgerlock.]
[Behind the Veil: The carapace is actually from what would have been the central, overarching threat of GSH. Had this campaign continued, there would have been a thread pointing north to the Redoubts and beyond to the High Desert to find out the truth.]
[Behind the Veil: The radio tower was essentially a last-ditch effort by the Church to get the Interface. Something spooked them (a visitation by Lady Badgerlock) and in their panic they attempted to bootstrap themselves into their own Interface, hoping that they could grab the Navigator and use it to patch over the crippling flaws of their own and help them ascend to divinity]
[Behind the Veil: The Beast, Lady Badgerlock, and the Third Man are all members of the same group. Their plans and rivalries were not yet developed by the time things fell apart, though I had some imaginings that the Third Man had his own agenda.]
So you see the basic pattern. Scatter seeds, a thread or two become major developments, others are weaved in where they might make sense. Don't let new elements overpower learning more about what's going on with the current thread. Make sure new developments are consistent with what happened previously.
Taking it Forward
I hope to be running Esoteric Enterprises soon, and that'll be a good opportunity to put this all into practice once again. Perhaps get better at converting my own notes into usable-for-other formats - seeds and threads lend themselves well to flowcharts (or if I wanted to get really out there, something like a Twine story with hyperlinks all over...wait...wait a god damn minute)
BRB that Twine idea is taking off you are witnessing the creative process in real time.