DM:
Thorfire, if you'd like to enter the dungeon unseen, make a stealth roll with advantage (DC 10).
Would like to keep things rolling, but need to know if Thorfire is going to try to sneak down into the dungeon. If he isn't able to post by the 24 hour mark (11:00 tonight), let's take a vote ("us" being Therarak, Celador, and Lazaret) on whether or not he tries it. Sneak into the dungeon, yes or no. Two votes wins.
...of course by that time, Thorfire will have logged in and decided anyway, but just in case he's unavailable, we'll have a way to keep things going.