An old, misanthropic and paranoid man feels his time is coming. There are sons to leave his fortune to, but they are not worth it, not a dime do they deserve! And he doesn't really trust anyone else. And so he has made a decision: as a part of his last will, his henchmen are instructed to burn and destroy all his holdings, buildings as harvest. The lands shall be auctioned off, the proceeds used to pay the servants. Nothing shall stay behind. Nothing.
Depending on the status of the grumpy old man, this weird occurrence may be only a family drama, or it may end up bringing an entire region into chaos. Or the son(s) have found what should happen, and want to prevent it before their sick father dies.
Adventurers are to capture an unknown monster for examination (for a sage or wizard) but they are themselves captured by the monsters, and researched.
Temple of some malign being invites you warmly and offers help (curing,needed spell etc) for some minor sacrifice . Sacrifices must be everytime bigger to work - up to living inteligent creatures. Maybe you pay some other price,too...
The adventure can take place in a slightly shifted reality, where everybody has a totem (an animal guardian). The totem should be chosen randomly and not by the player, it is ok if "Gorflin the Large," a gigantic and aggressive barbarian, has a mouse for a totem.
These totems will assist the characters in small way. It is up to the characters to determine how to get the assistance; the animals won't solve mysteries for the characters only supply the clues. The character may even have a dream where his or her totem actually speaks to them and reveals some sort of clue.
A vicious murder happens in a town that the party happens to pop in at. Under heavy suspicion as they are strangers, the party is forced to discover the perpetrator or have their reputations blackened, especially as more and more murders occur in the town, and mysteriously stop and restart when the party leaves to go kill off that evil necromancer who kidnapped the princess.
The only problem is that a demon, possessing one of the party, is the perpetrator. And the demon makes no signs that its living in the PC's head.
In fact, for all the party knows (except for the possessed person's), their companion is an evil murderer.
Do they try and execute their friend as he's a vicious murderer, and no evidence points to demonic posession? Or do they flee town with him, trusting him, and have their reputations destroyed?