The party was level 2 and fleeing from bounty hunters hired by a corrupt mayor, who was in turn bribed by a necromancer. The players quickly decided they probably shouldn’t travel along the road, so they trekked through the forest. I rolled randomly for weather turns out a storm was brewing, so I had the party roll perception,
I just sat there dumbstruck and laughed for a moment.
The players looked at me bug-eyed but nothing happened? An hour or so later at the table out of nowhere a massive Blue Chromatic dragon lands before them and combat begins. After the last player was unconscious, an NPC hunter happened by and woke up one of the characters. It was a hallucination. The party was confused until the hunter pointed out that they ate THOSE berries.
So the party raided the bush and kept THOSE berries.
A few months of real-time later they were interrogating a member of the thieves guild. Where they decided to force feed him THOSE berries. The guild member went into an epileptic fit and started frothing at the mouth begging it to stop, eventually, they would come to use THOSE berries on Then Necromancer as well as a King or two.
Turns out THOSE berries turned into a thing, widespread across the Kingdoms THOSE berries turned into a drug. The party then realized what they had done set off on a quest to stop people from making the drug.