A Randy Mystery is a side mission in South Park: The Fractured But Whole.
Plot details follow.
When you meet Randy outside his garage, he tasks you with finding the culprit of his car keying. Continue with the story missions to naturally come across the offender: Randy himself in The Bowels of the Beast. Beat up Randy to finish this mission.
As a result, you will be able to take a selfie with Randy in his house from Day Two.
|A Randy Mystery|
|The New Kid approaches the Marsh residence and finds Randy attempting to fix some damages on his car|
|Who would do such a thing? It's just so mean!|
|The New Kid speaks to Randy|
|Hey kid, you know anything about this? [shows the New Kid multiple scratches on the bonnet] Somebody is keying my wife's car at night. It's happening every night. I thought it was just one of you damn kids, but well... Here, come here, take a look at this.|
|Randy leads the New Kid into his garage|
|Whoever is scratching the car is also leaving notes. [pulls out a stack of notes] I'm just scared it's a... jilted lover or something. "You won't forget me that easy." "I thought we had something." "I'll tell the world about you, bitch." Listen, I'm sick of having to buff that shit out. If you can catch whoever's keying my wife's car tonight, I'll follow you on Coonstagram. Trust me: You want me as a follower - I'm a pretty big deal in this town. [takes a polishing machine and begins repairing the damage]|
|End of A Randy Mystery|