The designers did include a blank door for a GM to expand the dungeon,so I may use that to give Darkberry a chance to escape. Looking over the first few modules, Labyrinth seems to be the best jumping off point here for a low level character.
I'm happy with the Tunnels and Trolls system so far, the only thing I'm not terribly keen on so far is the simplicity of the monster stats. I do like how the system handles multiple monsters (two or more opponents can get deadly, fast), but I don't like how the stats have a hard time reflecting special attacks or abilities. This doesn't give the monsters much flavor and in the end you might as well be battling a statistic. The tinkerer in me can't help but think there has to be a better way and I have a few ideas I might try.
That and the low number of available monsters inspired me to grab my old D&D Monster Manual, my Talislanta Bestiary and any other crittercatalogue I could find and start thinking about conversions. The Wandering Monster table I plan on building is gonna be sick!