In the beginning, however, I actually had no idea what a helicopter seed was. So I was thinking about goblins riding around in magical helicopters. It was pretty bad.
My original idea was a group of PC wind-surfing on giant seeds down a spiraling chasm underneath a ruin, chasing a shape shifting child prodigy flying on a magic cello. Fortunately, I got a better idea.
My new idea straight out of an over-the-top horror game I ran in d20 Modern where if the party was giving a seed that they could plant in the ground and spontaneously grow a helicopter, they wouldn't be surprised (or wouldn't be surprised for long at least). Thankfully I got past that idea too. I was, however, then fixed on doing it as a Modern adventure.
In my experience with Modern adventures, however, it's way too easy to travel and get around, so even geographical "railroading" is rarely possible. That's why I tried to make the adventure more idea based than location based. I could see why that would be considered a weakness and looking back, that part could use a a lot more polish.
I probably spent 30% of my time brainstorming, doing research, and tying elements together, 30% writing the back story from those bare ideas, 20% writing the adventure part, and 20% editing/rewriting. It shows.
The assassin part could have been easily tied in by having Tannhauser going for the Pope, as well as Rome. A couple sentences to that effect would have made a big difference. I would say that the uses of the Cello to create earthquakes are historical as well (since it was Historical Doppelganger rather than Historical Doppelganger Assassin), but I definitely see the weakness of the assassin part I tied in there.
In retrospect, removing the hook with the Vatican hiring the PCs would have been a good idea, instead of half-assedly trying to keep it shoe-horned in later.
If anyone is curious, I think I spent about 6-7 hours on it in one sitting, then picked it up again 12 hours later and did another hour-or-so of editing and revising before (double) posting it.
Anyway, thank you for judging InVinoVeritas, I appreciate it. Hope all's well with the basement thing Tremorsense and I hope we'll see you around in future Iron DM challenges.