D&D One Shot

The PCs are imprisoned humans who must break a curse at a part-buried ranch. It might involve snakes.
There is a charismatic ruler who betrays them partway through.
The characters start during an attempted escape. Early on they encounter a new potential ally. If things get stuck a door opens.
At the end there is someone imprisoned.

The characters are scarred criminals who must auction off a necromantic staff. A character is celebrating a special anniversary.
It is at a haunted valley which is the birthplace of a fanatical champion.
There are skeletons performing a dance. And an unhappy king wants to complete a tavern crawl in the City of Brass.
At some point a deity sends an omen.
As the adventure progresses there are hints leading to a great betrayal

The PCs are young folk heroes who must solve mystery of why they are still alive. They all remember dying but not all the details. It might involve lycanthropes.
There is a rich rogue who hates one of the characters. they worked together with a character.
The characters start on a sinking vessel. Early on they encounter an unexpected admirer. If things are going nowhere a character learns something useful with a Religion check.
At the end there is a carnival.

The PCs are young gladiators who must establish a base in a decorated sea cave. The mood might be... deep
There is a repulsive villain who betrays them partway through.
The characters start outside some ruins. At some point they spot foes who are unaware of them. If things get stuck they receive a useful sending.
It finishes with a reward of fame and glory.

The PCs are old charlatans who must investigate the history of an enchanted chest. One or more characters have cursed magic items. It might involve skeletons.
There is a famous lizardfolk shaman who works against them. they grew up with a character.
The characters start on the road about to encounter someone. Early on they encounter a puzzle trap. If things get stuck they uncover a secret stockpile.
It finishes with an idyllic rural scene. Possible sequel... a clue from a reward or treasure points to an infamous dungeon...