This is a conversion of my entry in the One Page Dungeon Contest into a 4th Ed. specific Two Page Mini Delve.
I haven’t really added too much. I added some hooks for the DM to use both before and after the delve. These have become features of all my mini delves. I also added the standard stuff – skills and DCs, and a few combat specifics. Plus rules for a collapsing ceiling ported mostly from the Escape From The Badder Warren mini delve I did last year.
I think the biggest addition to the delve was the Minor Sphere of Annihilation. There does exist a Sphere of Annihilation in two similar forms already, and you are welcome to use the official rules for it. However, I wanted something very powerful and very dangerous for the PCs to play with that didn’t require an “attuned talisman.” I thought a difficult Arcana check should do the trick instead. So, a character can take control of the otherwise unattended sphere and move it around, but if they lose control of it…. well, it wouldn’t be good to lose control of it. I wouldn’t recommend losing control.
You can download the delve here.