I assume based on the thread that camping is taking place. Given the lack of healing in the party at this level I am going to adjust the healing rule of 1 HP from a full day to an eight hour uninterrupted rest. 1 HP restored... If you want to do a bit of Role-Playing now then feel free... You probably want to wait to fiddle with the Sarcophagus until after resting but I will include some information about it here. I'll keep an eye on the thread if RP isn't happening we can move it to spoilers and move forward with the 8 hours.
The arrow platform can be turned toward any of the seven tunnels. Of the seven tunnels two of them appear to be missing their lanterns (Indigo and Red). The only lantern that appears to be lite is the green one. Starting from the Orange lantern which the arrow is currently pointing at the platform can be turned clockwise to Yellow, Green, Blue, Indigo, Violent, back towards the stairwell, and finally around to Red before it could be returned to Orange.
Just a link to a google sheet to give you an idea about the lay out.