RPGMemes

Yeah, I think there's a big difference between "I thought they were going to investigate the smith, but they're really suspicious of the wizard now and want to check her out first" and "they decided to forget about the whole civil war for the throne thing and open a BBQ joint for the local goblins"

Nowadays I'd probably just explicitly be like "Hey, so, when we started this game we agreed on a certain tone and direction. Specifically, it was going to be about a power struggle for the throne. Running a restaurant business in D&D sounds wild, but that is really a different kind of story and a different game. If you want to do that, let's talk about it. Otherwise, I'm asking you to stay more on theme."

Though I say that and my best game had plenty of "beach episodes". One time literally, after they saved some sahaugin from being subjugated by a siren.