To get past the skeleton door to find Classi in The Thin White Line in South Park: The Fractured But Whole go into the morgue, pull back the bed on the left side and collect the forensics room key:
Go into the forensics room and go to the top left of the room. Enter investigation mode and hover over the electrical box and use Snap N Pops to pop it open:
Enter investigation mode and hover over the electrical box and select the hamster icon. Go to the highlighted area and follow the button prompts. Stand in front of the room to the right, open time controls to pause time and enter the room and collect the forensics cabinet key:
Go to the back of the room and open the forensics cabinet. Enter investigation mode and hover over the pipe nozzle and select the nozzle icon:
Go to the highlighted area and follow the button prompts. Go into the room to the right, enter investigation mode and highlight the green panel on the ground:
Select the hands icon. Go to the highlighted are and follow the button prompts. Pick up the skeleton key and use it to open the skeleton door.s
To find out who has been keying Randy’s car in A Randy Mystery in South Park wait until the first night. On your way you will encounter randy keying his car. After you beat him, the mission will be complete.