In our most recent session this past Sunday, the party met and drank with a local merchant who they'd met on the road, and agreed to sign a contract with him the next day (a contract to do something dangerous to benefit his business -- I'll skip it for now.) The same evening, though, they got to scheming: suppose they were to go and find this guy at home tomorrow morning, while hungover, and just take him out? That way they could earn the money he was going to pay them without having to do anything more dangerous than killing one small-time merchant.
The next day they set out, but the unofficial couriers don't keep addresses (you have to tell them where to go). A bust. By way of a quick lie could they get the merchant's home address out of the town records office ... only to find, when they arrived at the Street of Coopers, that he was not at home. Another bust, they thought.
Turning to go, they noticed a certain man exiting a metalworker's shop across the way. They knew him to had a thief and they'd had a short scuffle with him a day or two before. I'd already made it clear that there were people going up and down the lane, and students hearing a lecture in a small park nearby ... and being in town, the party had their weapons stowed out of sight.
"The guy notices you as he's hefting his sack. He glares, and approaches the steps where you're standing. What do you do?"
What followed was a exchange in which, among other things, the thief claimed he had lots of friends and was going to seek revenge on the party, and the party generally derided his skills and spat at his claims of having the ear of more powerful persons. It went on for at least 10 real-time minutes, almost non-stop, punctuated only short lulls and one "what do we do" huddle as the thief started to walk away. (They followed him and kept at it.)
This exchange was heated and incredibly tense. There were insults on both sides. There were threats and escalated counter-threats. The two sides almost, almost drew weapons ... but not quite. And the players were never 100% sure how to proceed.
I am proud that I roused the players with my little scenario, and I am proud of my players for absolutely blowing away my expectations for how much emotion I was going to elicit. I have to count this as a win for me, because I don't think I could have gotten this kind of emotional response out of players when I was younger and less experienced at DMing. I have had the first indication that three years of rustiness has been shaken off.