If the story has more than one MacGuffin, they're Plot Coupons. You just have to collect enough of them, and you can trade them all in for a denouement.
The use of plot coupons more or less garuntees that you are running a fetch quest.
Game and Story Use
- Introducing a matched set of MacGuffins is a way to fine-tune plot progression. You scatter them throughout your campaign setting, and sent the players off after them. By making the PCs go to different locations or scenes to collect them, you can control how quickly the story proceeds. If things bog down, you can surprise the players by having the next location contain the majority of the remaining plot coupons. If they PCs are cutting through all the obstacles too quickly and the campaign is failing to build tension, you scatter the coupons to the wind. They'll never know it wasn't exactly what you had planned back in the first session.
- In a particularly silly, snarky, or genre savvy campaign, you could hang a lampshade on it by sending the PCs on a quest to retrieve actual physical coupons. "Good for one tenth of one Wish. Void where prohibited."