So, was working on a pug Jelly King run when I get the boot @ depth 14 right next to the elevator to the Garden of Goo (thanks Smevz and your guildmate).
I don't trust my ability to solo, but would really not have wasted the energy to get this far down and not complete it. If I wait around long enough will a random party join me, or do I have to invite them? Can I invite them at this level? I assume you can, otherwise getting the boot from the pug doesn't make much sense (thanks again Smevz and random guildmate).
If your party is open then people that choose to party up will be randomly assigned to you.