A similar thing happened with my players, I added in an additional encounter, a patrol returning from the wilds which was tasked with checking over the areas recently decimated by the PC's, they set up an ambush for the PCs just outside of the excavation chamber (I used the level 3 Goblin Encounter group from the MM), and utilising the secret door to attempt to get behind the PCs- it was an awesome fight, particularly as Balgrun the Fat and his buddies got involved turning it into a level 5 or 6 (I can't remember which) encounter. It was pretty brutal but the players got through it- just.
I also re-populated the entrance chamber with the Goblins et al from the torture chamber (and a few of Balgrun's), the players (level 2 pre-gens) smashed their way through and cleared the exit- for an hour or so they thought they were stuck down there though, it made for some excellent do-or-die play.
I ruled that Balgrun didn't want to alert the Hobgoblins yet as it would damage his standing, besides he wasn't sure whether the PCs were still in the lair- no one was going down into the Rat/Jelly/Kruthik because they were off limits (deadly to Goblins).
As I say it worked a treat- good luck to you, and your players.
Cheers
I also re-populated the entrance chamber with the Goblins et al from the torture chamber (and a few of Balgrun's), the players (level 2 pre-gens) smashed their way through and cleared the exit- for an hour or so they thought they were stuck down there though, it made for some excellent do-or-die play.
I ruled that Balgrun didn't want to alert the Hobgoblins yet as it would damage his standing, besides he wasn't sure whether the PCs were still in the lair- no one was going down into the Rat/Jelly/Kruthik because they were off limits (deadly to Goblins).
As I say it worked a treat- good luck to you, and your players.
Cheers