I'm playing RtL as the Overlord, and I hit a point that I was unclear on in the rules.
The heroes are in a dungeon, and they've cleared out the first level. One by one, they enter the portal to travel to the second level. The last hero takes her turn and enters the portal - now all of the heroes have gone. Normally, when the heroes have all taken their turns, it becomes the Overlord's turn, but with all the heroes now in transit, they should immediately be transported to the next dungeon level.
Which happens first, the Overlord taking a turn, or setting up the next dungeon level? If the dungeon level setup happens first, can the Overlord take a turn after the new dungeon level has been set up, but before the heroes have had a chance to act? Does that mean the newly-set-up monsters could all rush forward and attack the heroes who have just emerged from the portal?