I need ideas for 'incidents' and the like to throw at the PCs during a dungeon crawl scenario that has a bit of intrigue and backstabbing going on amongst the NPCs.

If anyone knows of a published scenario for any genre or system, that has a) an expedition b) someone with an agenda and c) events or a timeline related to that agenda then I'd love to know. Maybe I can scour it for ideas. This is fantasy but something scifi or pulp might be as useful.

The PCs are tracking a cabal of cultists seeking 4 elemental relics. The PCs have the air relic. At  the  earth temple they find an expedition organised by a noble to find his father's tomb located within. Assisting him is a scholar and a merchant. All with numerous lackeys and hirelings. Are any of these really the cultists seeking the relic? Well yes of course...

The bad guy is the merchant and some lackeys. He seeded the way for the noble to come here. He needs him to get access to the heart of the temple. To do that numerous mechanisms need to be activated in sequence. As the nobles father enabled this sequence maybe the noble has an idea.

The spirit of the nobles father has become the relic's guardian. He will use denizens and traps to foil the expedition, but wont harm the son. The cultist knows this too and will always be near the son if danger presents itself. The cultist also knows the PCs have the air relic but wont confront them until he has the one that's here. He will try and have the other PCs bumped off though.

The PCs need to figure who is genuine. The fact the noble seems to survive incidents will be quite a red flag. The merchant will generaly be friendly and will deflect any accusations against him (or the noble) towards the scholar or any expendable scapegoat. The scholar smells a rat and assumes the PCs are part of it. For a while they will probably think he is the cultist.

I need incidents to throw in while they assist the expedition. I'd prefer more generic ideas rather than ones needing me to expand on the background. Any suggestions that work with the situation as  presented would be useful. Feel free to fill in the blanks, maybe it'll be something I can use.

It seems like the spirit of the guardian father would be your best bet as a source for incidents. If he knows the merchant is a bad guy then he would come up with ways to try and warn his son. I don't know what powers and abilities he has to work with though. Another source of incidents can come from the cultists allies. He could have some of his lackeys follow the group into the tomb and cause mischief for the other explorers, especially if they were stealthy and at least one of them had invisibility magic.

The specific incidents will depend largely on the tomb itself, the chambers, and corridors and their contents.

The father has kinda been consumed by the elemental forces so he's largely mindless and going on instinct. Just with some vestigial urge (?) that the son is important to him. If he wasn't he'd pretty much go for the merchant instantly. Pretty much anything a powerful elemental could do in a temple dedictated to the element of earth is on the table for what is possible.

Throughout the complex are sub shrines to different metals all with various trapped mechanisms to restrict unwanted access. The denizens have some limitations to where they can get to and cant just pass through any wall. In many respects this an atypical dungeon with atypical dungeon hazards.

It isnt really idea for traps and dungeon hazards where I'm stuck for ideas. Its things where clues to who the cultist might be.

As an example one of the cultists gets offed in a trap. Its revealed he was in disguise and of a race that  have protruding canines that he was filing down.  He was clearly not what he pretended to be. So questions such as: So who hired him? And who recommended he was hired etc. Are going to arise.