Following someone through a dungeon. How to make this interesting?

[HotRoute]

Hi!

My party is tracking a higher-level adventuring party. The NPC party is traveling faster than the PC party towards a dungeon - so, when the PC party shows up at the site, the NPC party will already have gone in. I know I could have the dungeon mechanically reset itself, but I think this is a pretty unique situation and would want to do something more interesting if I could. I want something more fun for the group to go through besides unlocked doors and dead enemy corpses.

Has anyone run something like this before? Any ideas? Thanks in advance!

[Honest Tiefling]

1. They find corpses...Of the party themselves. Unlooted, too. Perhaps someone in the higher level party was a traitor. Or even just being framed as a traitor. For extra fun, have the body come to life as an undead.

2. They didn't kill the enemy, just disabled it. And boy is it pissed off NOW.

3. There are multiple paths. They could take the safe path with no loot, or go the path that the higher level party didn't...Which is still going to be full of traps and the like. Perhaps a spell or other actions done by the higher level party created a cave in, so the lower level party can't follow the same path and have to go around. Possibly into segments of the dungeon not previously explored.

4. The higher level party either knows of the lower level's existence, or is blissfully unaware. Either way, they leave traps and other nasty surprises behind them on purpose to get rid of pursuit.

5. The higher level party has a time limit on whatever they are doing. So while they might grab anything magical, there is still some loot that someone trained in History would know would fetch a good price if you found the right buyer.

6. The higher level party cut themselves off from the exit somehow (room got flooded, cave in, etc.). Does the lower level party help or hinder? If the higher level party is meant as a boss, then it is a single member who is reconsidering their employment options, but is too injured to help heavily.

[lunaticfringe]

The dungeon was full of Trolls, the lower level PCs must now fight the still living Limbs and body parts.

[solidork]

This could actually be potentially pretty interesting.

1. There could be scavengers picking over the bodies of the enemies the other party killed. Carrion Crawlers are the classic option.
2. They could fight some monsters that were only nearly killed, but still hanging on. Don't just throw in some scary stuff with low HP, since in D&D you don't get any less effective at fighting no matter how hurt you are.
3. The higher level party could have bypassed some obstacles with magic that the PC party doesn't have.
4. The higher level adventurers engage the final boss of the dungeon while the PCs are part way though, triggering some kind of dungeon wide event. The first thing that comes to mind is that all of the corpses reanimate as zombies. You could foreshadow this with carvings and the like beforehand.