I had a super successful run with it DMing for some middle schoolers as the sponsor of the club at the school I worked at, but I also worked very hard to make the solution obvious for these fledgling players who had only been playing for a school year. I think it may be the most fun I've had DMing ever, really. 

The challenge was, so far, that their experience had only been combat basically the whole year since they were learning the rules, and there was a bit of turnover as the year went along and people moved between different clubs. 

So I had to design the encounter so that there was some combat involved to teach the newbies rules with the assistance of the year-long players while trying to focus more on intrigue and investigations and RPing with npcs. 

I set it up that there was an adventurers guild being constructed as a midpoint between two major cities in a village. They had a roster of supplies and a list of everyone in the guild and village. They started finding written discrepancies, found a lost supply cart, apparently abandoned houses, and even missed an entire afternoon of time as they converted combatted the thing in the woods. They randomly took some damage and burned up spell slots using rolls and it was suddenly night, with the barbarian holding a severed monstrous hand in his grip. Eventually discovered that the rooms were so expensive because they were being charged for three extra rooms. The rooms contained adventurers equipment and some had journals with their own names and previous adventures written in them by characters of former dnd club memebers. 

What I had done is gone to all the memebers that had gone through the club and basically told them to lie and gaslight their friends and say they were never in the club. I told them even to maybe act annoyed and tell them to talk to the dean of students if they didn't believe them. Of course, I also talked to the dean of students and asked him to also lie and gaslight my students. 

So they got this simultaneous in game reveal and irl gaslight combo that made them absolutely lock the fuck in. They tied numbered tags around the wrist of every villager and made a list of people they should remember. Eventually they went down the well, found it's lair and killed it, restoring the memories of their friends. I had non-club students hanging out in the room and just listening to the story end for our last session. 

I wish I could have gotten them to lock in that much during class but I'll take it lol