My longest "one shot" ever ended up taking 52 sessions over a little more than two years. What started as a very simple local festival where the party tried to win a cooking competition led to (not in order):
- one of the largest inns in town burned to the ground
- one party member pregnant with twins from two different fathers (one of them a different party member)
- at least six assistants of one of the other chefs dead by the hand of the one party member that has the worst combat skills
- the same party member killing a local merchant with a single punch in the face after he was accused of stealing when the thief was really a different party member (the pregnant one)
- one party member waking up in the Empress' bed with a black rose on the pillow next to him
- one supernatural STD sent by the goddess of (essentially) sex, drugs and rock & roll ravaging the whole barony
- the one session where they visited said goddess' temple being the only occasion where they were super PG-13
I know at least one of my players reads this community so feel free to add anything that I may have missed.