The adventure from last session was Fruiting Towers, from Fight On! #13, authored by yours truly. So if you want to see what's what with the tower-crusted hill, now you know where to go for more details. I made a deliberate choice in that adventure to use book treasure to save space, instead of coming up with unique items, so I had to tweak the censer on the fly to have a little more flavor.
It's fairly easy to figure out who Mongo's new character is - witness the ignoble death of henchwoman "Click."
The house rules I've got on character death revolve around how far the party has penetrated the dungeon. If a single PC dies, they can bring in a new character at a level equivalent to the deepest level the party has found, minus one. Since they spent 30 seconds in the 4th level, that means new PC's start at 3rd level. If there's a total party wipeout, then new PC's get to start with levels equal to the deepest level, period. There is an incentive to go deeper to just peek at the lower levels, but my players are fairly cowardly, so they've been ignoring the many staircases they've found.
My one regret from the last session is my complete failure to roll a single wandering monster encounter as they traipsed around the countryside. Ahh well, I almost always let the dice roll as they will, not as I want.